Forecast transaction costs

[Aussieintoit]

Hi I'm new here but have been reading/watching what I can to come up to speed on how the whole blockchain/Bitcoin thing works.

I have a question which I hope someone can answer for me. As I understand it,

1)A miner is issued with a reward for new block creation in the form of new Bitcoin issued, but the amount of Bitcoin reward per Block created will reduce over time. (Hence unless the price of a Bitcoin increases, the reward per Block created will reduce over time)
2)The cost to solve the problem required to create a Block will increase over time due to the increasing difficulty & hence processing power/time required.

So the reward per block and hence reward for transaction facilitation will reduce over time (assuming Bitcoin value stays constant), but the cost of producing the block will increase over time (due to the more difficult problems and higher processing power required.) So my question is if the value of Bitcoins stays constant, and the miners costs/block are increasing and their reward/block is decreasing so why would a miner continue to mine?

A related question is if the cost to solve the problem to create a Block is increasing and the number of transactions requiring a Block is also increasing, would the cost to facilitate the transaction not also be expected to increase over time? Would this not be a big disincentive for more widespread adoption of Bitcoin for transactions?

What am I missing/misunderstanding? Any help would be most appreciated....






 

[cupronickel]

Current mining produces rewards both in new Bitcoin and in transaction fees. As coin production eases off until it eventually disappears with the last coins created, TX fees will take over from Bitcoin creation as reward to miners. The fees vary depending on how full the mempool is. Thus transaction cost is predictable, since there's an algo behind it.

Take a look at these two resources to explore tx fees & mempool more:

https://jochen-hoenicke.de/queue/ (here, you'll immediately notice that weekends are cheaper and the effect of the Bcash spam hitting the mempool)

https://bitcoinfees.earn.com/ (read the text after the charts, these explain the fee calcs)

[mocacinno]

cupronickel  is correct, i only wanted to add following remark:

There is no law that says the difficulty HAS to rise, nor that the cost of mining HAS to increase. As a matter of fact,  the difficulty has dropped in the past (altough the general trend seems to be upward).
Also, when new ASIC's hit the market, they're usually a lot more performant (they produce a higher hashrate with the same power draw), so they difficulty can actually stay status quo while the hashrate (and difficulty) keeps rising, while in the same time the power use drops (so the average cost drops).