I'm a long time Google FI user, but the Pandemic has caused me to reevaluate my phone providers and look at other available options.
I've been playing with eSim stores like Airalo, Nomad, Dent, Truphone, US Mobile.
Since I've been locked down due to the covid restrictions, I've not had a chance to go overseas to test these. I did download a 1GB USA esim from Airalo, Dent, US Mobile. All three operated on the AT&T network. All three also had latency ~ 250-350ms. Of the ones I tried the US Mobile esim (resold truphone) I think was the closest to native AT&T speeds... achieving 70mbps down at my home. The others were slower but still pretty decent around 20-30mbps. I noticed that the Dent and US-Mobile esims took FOREVER to activate... but once they did they worked well. The airalo and dent esims were the only ones with a reasonable way of "topping" them off with more cash.
Long story short, I think we are entering a whole new phase in the mobile data world. FI's $10/GB is suddenly not looking as great as it once was, although they still have be most convenient and trouble-free service IMO. T-Mobile's 15GB for $50 plan is still pricy but is also a low-hassle option. These new eSim stores however have T-Mo beat in that you won't get nastygrams for actually using the data you bought.