The block subsidy is decreasing exponentially. Currently it is ₿3.125, at block 1,050,000 it will drop to ₿1.60625, at block 1,260,000 it will drop to ₿0.803125 per block and so forth. In about 15 years, it will be slightly more than ₿0.1 per block. ₿1 in transaction fees is about a full block at 100 sats/vB. So, a block subsidy of ₿0.1 is exceeded by fees, if the transactions pay more than 10 sats/vB in average. As you can see, this is becoming relevant a bit earlier than in 100 years.