mining altcoins is usually dependent on what you mine. most people invest in GPUs and mine GPU mining coins. and the most famous one of these use to be ethereum and because of its difficulty, fast blocks, huge block reward and also the pumping price, mining it became very profitable. so it was good to buy equipment so far for mining.

but the difficulty is higher, the pump stopped, and to top it all, they are killing the PoW and with it mining.

in other words if you can find another coin that is pumping with a lot of noise, or has a more solid price and can easily be mined then invest. otherwise i say investing in mining at this point is not worth it.