You can get 5.02% if you bring $100k to them anytime. They only make it available in a Merrill CMA (cash management account) though (see preferred deposit in pdf below). You can also reduce that $100k to $1 after you make the initial deposit and still maintain access to that savings rate.
If you want an FDIC-insured savings account from a large institution, Marcus offers 4.4%, and it isn't even the highest -- Synchrony isn't as big a name but it offers 4.75%.
And while I can see keeping an intermediate buffer in such an account (since you can ACH directly from it), it's not much more hassle to use a money market fund (details do matter a little), e.g. FZFXX, VUSXX, or SNSXX (those are Treasury funds; prime funds typically give a slightly higher rate), for around 5%. Even there you're giving up a little vs. laddering T-bills, but it's so easy and it's completely liquid.
The only reason not everybody does this has to be that they're just not used to brokerage accounts, or that they don't have enough money to bother.
Probably most people who want to hold cash should just open an account at Fidelity, and put any money that can afford a couple day's lead time into FZFXX.
Ally bank offers over 4% for any amount, and has a no-penalty CD (you can close the account at any time, they use a trust behind the scenes) offering 4.5% iirc.
A few banks have been offering 4.00 or higher for the past 9 months or more. The apple card with Goldman Savings is currently at 4.15% and has been since it launched. It was mostly smaller banks that I saw offers in this range, but It looks like the bigger banks have to play along now, lest they lose more inflow.
