Original brawl was a legit great idea as an on ramp for newbies.
I don't even say that just personally, but just in what I'd see from friends of mine who are
very casual in magic. They would just buy a box, and then throw all the vampire cards they got into a deck. Or all the zombies. Or all the trolls. No concern for how "competitive" it was, just that it looked fun. (In fact more than a few times I had to help them "tune" it because sometimes the decks would be downright unplayable because they messed up the land ratios or something.)
As originally designed, Brawl was ideal for on-ramping. New player got a shiny looking legendary? (creature or planeswalker?) Well let them show it off by making it a commander and they'll almost naturally just throw in anything vaguely related to it.
Plus having it be standard focused is easier since newbies can get new sets easier. Also the singleton rule makes it a lower cost of entry as I'd be willing to pay up to $10 for a single card I need... not as much as $40+ for 4 copies... (or in arena just using 1 wild card instead of 4) Even keeping the deck smaller at 60 and having life be 25~30 gave you some more time to play the game but didn't make it an endless slog. You could still have that social, diplomatic effort....
That is all.... IN THEORY.
Of course WotC had to go and mess it up. (How I wish the brawl decks of Eldraine became standard tie-in products instead of those commander decks - I don't really need 100 new cards shoved into a collection I'm trying to trim every time a new deck releases I half want to build around, 60 would be plenty.)
I'm not even sure why arena became so obsessed with trying to recreate commander in the first place. It's like they thought 100 cards was the key factor of the game, not the "sit around and have fun with friends" part. Especially when it's 1v1, 60 is plenty. That's not even getting into the stupid arena timer and how much a 100 card deck can eat into that.
Oh well.
Still my favorite brawl deck.