Because the people you subscribe to are making those shorts.
Your subscription page shows you all the most recent videos from the channels you’re subscribed to.
That in no way is shoving anything down your throat. You’re just supposed to watch what you want to watch. You’re not expected to click and watch every video in your subscription feed.
And unfortunately many YouTubers who do make normal, good content also make shorts because it's incredibly algorithm-friendly, so there's no avoiding it unless you blacklist every creator that dares make shorts.
Of course, I then see one row of videos and then the damn "YouTube Playable" section so maybe the moral of the story is that the main page is unusable outright.
An “entire section” isn’t “shoving” something down your throat. You literally don’t even have to process that part of the site with your brain.
When you go to Amazon are you just completely overwhelmed by all the stuff they’re “shoving down your throat”? I mean they have tons of sections on the home page. Are you actually bothered by that or are do you simply search for what you want like everyone else?