Without interference, I believe BTC will climb to $ 150K in 2024 and $ 400-500K by 2028. If mining reward drops down to .00015 next halving. it appears I can mine around .25 BTC in 5 years with a 141TH XP. Still profitable factoring in .075/KHW based on the projected BTC price.
S19 XP 141
Current BTC mined per day 0.0003
https://www.coinwarz.com/mining/bitcoin/calculator?h=140.00&p=3010.00&pc=0.07&pf=0.00&d=52350439455487.00000000&r=6.25&er=1&btcer=30000&ha=TH&hc=5000.00&hs=0&hq=1
After Halving it drops to 0.00017
https://www.coinwarz.com/mining/bitcoin/calculator?h=140.00&p=3010.00&pc=0.07&pf=0.00&d=52350439455487.00000000&r=3.125&er=1&btcer=30000.00000000&ha=TH&hc=5000.00&hs=0&hq=1
Current BTC mined per day 0.0003
https://www.coinwarz.com/mining/bitcoin/calculator?h=140.00&p=3010.00&pc=0.07&pf=0.00&d=52350439455487.00000000&r=6.25&er=1&btcer=30000&ha=TH&hc=5000.00&hs=0&hq=1
After Halving it drops to 0.00017
https://www.coinwarz.com/mining/bitcoin/calculator?h=140.00&p=3010.00&pc=0.07&pf=0.00&d=52350439455487.00000000&r=3.125&er=1&btcer=30000.00000000&ha=TH&hc=5000.00&hs=0&hq=1
You're forgetting difficulty will also go up if the price will do so, in your scenario when Bitcoin is at 400 000, the reward per th/s is 50 cents compared to 7 now and miners will not plug additional gear when an S19 is making 70$ a day burning 5$ of power?
Use this:
https://insights.braiins.com/en/profitability-calculator
Play with both the price adjustment and the difficulty, throw in the fact that your gear might go boom, your energy price might go up twice and then you have a better picture of it!
3. No, they cant except they can have 51% control over the blockchain without that would end up creating an hard fork like BCH, thus an altcoin
Even if they have 99.9% of the hashrate it doesn't mean a thing, let's not even think of the other fact, they have 99.9% of the hashrate and they decide to make the coin go Pos? lol! No matter how much hash rate you have you will not be able to stop anyone to ignore and never stop using the old code!
3. I guess it's possible if they will acquire at least 51% of all Bitcoin hashing power.
No, it's not, that's not how a fork works.
They could do it without a single S1 mining and they could end with a dead coin like Bitcoin gold when if they had 99.00% of the hashing power.