A series of 20 or more losses in a row can happen literally from your very first bet because everything depends on luck. So, it's worth noting that the martingale strategy sometimes doesn't really work on short distances, and I agree with you that it's pointless on long distances.
I guess it depends on the game you're playing. If you're playing slots, then yes, a losing streak can be even longer, but there’s probably no point in applying the Martingale
systemstrategy to slots. And if you’re having a 20-loss streak in betting, then maybe it’s time to consider stopping those bets, because clearly, you’re not very good at that particular game. The Martingale
systemstrategy in gambling has been discussed countless times, but I’ve never seen a single player say it’s a good idea.