The irony is that pre-WotC D&D arguably handled scaling way better, since the "soft cap" was far lower. So, sure, you could get to level 20 (or further), but you would've been feature complete by around 10th level, with HP scaling dropping to a crawl (I believe 1e Fighter were the only class that got HP after 9th level, and it was only 3 per level? It's been a while, so don't quote me on that). Name level was effectively retirement age, and the rules for playing past that point were mostly aspirational.