Schwab VS Fidelity

I’m heavy in Fidelity but recently setup Schwab fo my kids so they can buy fractional shares. Are both equivalent or does one have any significant advantages over the long run? I have extremely simple investment strategy of basically buying VTI and FZROX monthly to max out nontaxable and build a taxable brokerage acct I can use as an asset for extremely low cost borrowing in future.