Conclusion
Now is the time to go into mining and buying of Bitcoin as each halving reduces the block reward by 2 which causes scarcity that has the potential of increasing price.
I think that there is actually no guarantee that we will have any BTC mining facilities after a century. So, yes, the best way to get some profit out of mining is to start mining now. Later there can be many issues: not only technical, but also legal. Moreover, there will be numerous blockchain projects in the future, most of them will require specific mining facilities. So the only way to get some knowledge about mining algorithms is to start mining with the tools we can afford now.
There is actually no guarantee that we will not have any BTC mining facilities after a century. So the statement goes either way but I agree that to take advantage of the block reward, a person who have plan to engage in Bitcoin mining activity must do it as soon as possible because Bitcoin blockreward will keep on decreasing every 4 years, and if the person who wanted to engaged in mining delay his plan, he will be only at lost if he do it years later. Just like if he got fund and plan to setup the mining farm on 2025, he will be missing out on the current block reward since he could have enjoyed the current block reward that is two times the reward of 2025.