Are Fidelity, Schwab, and Vanguard overrated compared to bank brokerages?

I see the big three recommended a lot but if I'm just buying and holding ETFs, I don't see much of an advantage over something like Merrill or JP Morgan.

With the latter two, I can have my banking needs and investments all in one place.

Also, $100,000 in Merrill gets you a 75% boost to your credit card bonuses giving you some of the best in the country.

And bank brokerages don't seem universally worse like how JP Morgan allows fractional shares while Schwab doesn't.

With Merrill I get the convenience of having investments with my banking, the same commission-free trades, and the best credit cards in the US along with priority customer service.

I see the big three recommended on reddit so much but I don't see the benefit for a buy and hold investor like myself who already banks with Chase and Bank of America.