Building a mining rig isn’t “difficult” per say, it’s can just be really really frustrating.

Skills you need:

    Patience - yes, you’re dealing with hardware (it’s better now I suppose) but there are still electronic problems that arise
    Basic computer building skills - understanding what goes where, what types of things you need to build a desktop from the ground up
    Great research ability - everything is on Google or Reddit or Bitcoin talk forum, so you just have to know where to look and what to search for
    Basic understanding of networks (if you plan on running more than one computer on one network and run into router problems)
    Basic understanding of power usage & electrical outlets (if you plan on running more than 6 cards on one machine or more than one 6-card rig in your house / condo / apartment)

That’s about it.

Common problems you’ll run into:

    overloading electrical outlets
    blue screen of death for unknown reasons
    driver challenges

Good luck!

No, I highly doubt it.

Bitcoin is a system that aims to facilitate transactions without the need for a bank.

People tend to overlook the fact that anywhere where one transacts value in different forms inevitably forms an economy. There shall be tools and factors that influence this economy to cultivate it. Banks are just one of the factors that influence economy. Banks run within a different kind of economy. Banks are designed to safeguard people’s money, lend the same money to people that need them to collect interest and eventually have the money rotated within to generate maximum value per rotation.

Bitcoin’s economic model differs from that of a bank.
Cryptocurrencies (bitcoin) might solve a problem that banks do too,but

Are they catering to the same economy ?
Banks are present to safeguard customer’s cash holdings at a given time and lend them to those in need to collect revenue in the form of interests, that involves a central authority catering to needs of the public. They usually cater to specific locations and factors that decide their existence is the ratio between people having accounts/money in the bank to people willing to borrow money at set interest rates. Value of currency is subject to inflation. Tokens(Paper currency) aren’t capped and are issued by the government.

Bitcoin is an investment similar system that isn’t controlled by a central authority, but instead controlled by consensus. Bitcoin can be accessed and obtained by anyone with access to the internet but does not cater to the needs of the general public on an ad hoc basis. Any changes to be made are made on a consensus basis. The system controls the number of tokens(21 million) that can be issued/revolved ensuring that rotation of Bitcoin shall only increase its value.
By keeping the supply constant, demand shall dictate the value of Bitcoin and given that value is being generated in each round of rotation, the value of Bitcoin shall only increase.

Conclusion: No, they aren’t catering to the same economy.

Are they following the same or similar economic models ?
Banks are to remain profitable from the interest they make from lending leveraged account holder’s money.
Bitcoin shall continue to exist if the demand for its tokens continue to grow.

Conclusion: No, they aren’t following same or similar economic models.

Are they generating a high value per rotation of money within the system ?
Banks are subject to inflation. They make profit from interest accrued from lending account holder’s money to remain active, but they are affected by external factors such as government laws and their issual of local currency.
Bitcoin, by keeping the supply constant, demand shall dictate the value of Bitcoin and given that value is being generated in each round of rotation, the value of Bitcoin shall only increase. Bitcoin isn’t affected by government laws and has a capped supply which keeps its motive in alignment with that of its token holders.

Conclusion: Yes, both generate a high value per rotation within their system.

How flexible are they in moments of need/ crisis ?
Banks are limited by flexibility to help their customers as long as they remain profitable. Banks, being controlled by government and a central authority plays an important role.
Bitcoin are only as flexible as its consensus deems it to be. Bitcoin on being controlled by consensus and demand plays an important role.

Conclusion: Both are flexible and inflexible within their very own spheres.

Are they sustainable in the long run ?
Banks are sustainable as long as they continue to make profits from leveraging loans and account holder’s money.

Bitcoin is sustainable as long as there is demand, community and transactions happening within.

Conclusion: Both are sustainable in the long run as they cater to different economies.

Bitcoin and Banks are catering different sections of our society.
Sure, one might hamper another, but I don’t think it is enough to erase one’s need to our society.

I’ve used a couple of comparisons to validate its need although there are a lot more factors that come into play when economic models are concerned.
Both have had considerable thought and work put into its making and hence both remain unique within their own spheres of influence.

Ref:
Economy - Wikipedia

I hope this was helpful.

Good Luck!