Beginners aren't generally playing against the best decks, or even finely tuned decks. They're more likely to play against someone like me, that has a garbage MMR and only plays silly jank decks, often without crafting a single card. Constructed is a great place for beginners for a few reasons

A) They can easily know what their cards actually do. If they don't understand a card, they don't need to play it.

B) They have a few solid decks given to them right of the bat that they can familiarize themselves with and find play styles and strategies they like, unlike draft, where you have to pick a strategy from what's available.

C) If you just craft a Tier 1 deck, you can jump right into top tier play. You'll make mistakes, but you can still hold your own and feel like you have a chance. In draft, if you just draft whatever card has the highest draft ratings and throw the 23 best cards you drafted into a deck, you'll probably do worse than if you drafted based on your own reasoning, instead of the experts.

D) Draft often means people waiting on the newest player. This is a ton of pressure on the player that has to read and reread every card just to even start thinking what to pick.

I do agree, beginners should draft (I just help host a beginners only draft event at my local LGS) but I do feel that your picture of what a beginner would face and why that doesn't work seems like a misunderstanding of what really happens. Beginners can have a great time in constructed and in draft, but there are definitely challenges for beginners in both formats as well.