Polygon has potential to be like ethereum because less fee and fast so I'm pretty sure that many project team will prefer polygon network in the future.. It will be popular just like ethereum and also the price will skyrocket and reach $100 price, so polygon is my choice good for long term investment.
Isn't it true that polygon already experienced its major bull cycle, so there are less chances that it would go into another bull cycle to give exponential returns. My best speculation would be to invest in a coin that isn't that popular now and is also having the features of coins like polygon, ethereum etc. I also like BNB but have stopped investing in BNB for now as there wasn't much movement in its price from a very long time, but I am really inclined towards BNB to give good returns once it become more popular for ICO and new tokens.