ethereum and binance are good and trustworthy altcoins, I think you are on the right path to choose an altcoin for investing, but xrp I don't choose it, even though this is an altcoin that has lasted a long time and is at the top, but I don't choose it, in fact cardano, polygon, litecoin are my next choice, litecoin seems to be sleeping but I'm sure that later it will actually provide good profits in the next bullish season, while polygon has not yet shown its performance, even though yesterday it touched $ 1.5 but it's back down at $0.9, but fundamentally I think it's worth it
Not sure about Litecoin or Cardano, but definitely have to agree with you on Polygon. They are doing so much and attracting so many new projects. They have stopped funding for new projects however (as far as I know) but have the Polygon Village program now which is a great support program. We joined it with our project and it's been super.