for me it's better to mine than to buy because I want to start from scratch for success
This remark .... I can't figure this out.
Success has nothing at all to do with starting anytime.
Example 1: Bob has a nice gaming machine, which has a 1080Ti. Bob can earn about $7 per day on NiceHash with this machine, or more realistically about $5 per day while he works and sleeps. Bob is not interested in putting "RL money" (as Bob sees it) into Crypto, so Bob should mine away - he's doing OK.
Example 2: Fred wants to spend $1000 either on a mining machine or on currency. Fred likes the thoughts of mining, because he's tech-inclined. But Fred realises that getting his $1000 back is going to take a lot of time, and in the meantime, he's missing all that lovely crypto-volatility, and ensuing profits/losses. Fred should probably buy, perhaps trade.
Example 3: Jeremy (I'm running out of names, dammit) has $5000 which he wants to invest. Jeremy believes in crypto as a long term fix for many real world issues. Jeremy has been a travel agent for 30 years, and this represents a fair amount of his free capital. He does not like trading. Jeremy should research his projects, then buy and hold.
Jeremy, Fred and Bob are not real people, and there are many layers in between these examples. All are valid, depending on what your gut, the market, and your personal belief tell you.
"Start from scratch for success".....nope. Nobody gave anyone a medal for reinventing the wheel.