I think many aspect have to check for investing in which one cryptocurrency from transaction volume until the current standing at CMC are top 50 standing or not. Transaction volume in daily day or monthly in one cryptocurrency is very important when lack or decreasing of transaction volume easily for delisting on top exchange market, be careful when investing in some coins with lower transaction volume.
Important side have to check with team advice behind the project coins team, we don't know how trust them and make more analyze when investing in some coins.
There are many potential coins available that can be used as investments. I really agree that we just use the best ranking on CMC to determine where we will put the funds we have for investment. Indeed, there are those who first pay attention to the volume of transactions that occur on each coin, and it is legal to do so because it is a sign that the coin is very effective in trading.
But for sure, of course, Bitcoin, Ethereum, BNB, SOL, DOGE can really be used as a reference for making investments. Just adjust them to existing funds.