I'm in a 20 team league and it's highly competitive. Yes, 20 teams means 8 teams might be without a QB for a bye week, but that's where you need to weigh up drafting strategy. Do you draft a bench QB or take a position of need instead? Do you try to trade for a QB during your QBs bye week?
It's all good and there are ways around it. Of course a QB could get benched and you could swoop in and claim the 2nd string off waivers. Many options.
it's cutthroat, this league. One mistake, or one big injury, and you can easily lose 4 weeks in a row.