This is an ongoing discussion and I agree that it is better to just find single value bets than to place combi bets. Yes it is a nice feeling to hit one and than the payout will also be a lot larger than compared to a single bet, but how profitable is it? I like stats and I kept track of all my bets some years ago and the main conclusion was that, at least for me, placing combo bets will not result in a positive ROI
It is very difficult to give unequivocal advice here, and you are right, this discussion will never stop. My experience also shows that single sports betting has a positive ROI.
Although from time to time I put combo bets, but it's purely entertainment and here you can't do without luck.