How to find the best possible internet solution for WFH? Area code 65742, rural-ish MO.

Trying to help my parents find a faster option than their current AT&T Internet25 plan which is fine if only one or the other of them are at home.  But most often they are both working at home at same time, both needing to do high email volume, MS Teams calls, and VOIP phone calls.  Our family of 4 is on a group wireless plan which has the "business unlimited plus with private wifi multi line" so their hotspots through that plan provide a good backstop, but they consistently hit their max high speed data before the billing cycle is over.

For the sake of simplicity even if it isn't the most cost-effective method, is there any option through AT&T wireless and/or internet to bring it up to 100MB?

And if my parents are maxed out on AT&T offerings, then basically is this what people talk about when they say we need to invest in rural broadband?

Going further down this rabbit hole....

I spoke to an ISP local to 65742 area who does business hookups and they said even if they were willing to do a hookup to a house, the smallest plan they could do would be like $500/mo.

The only other options that I can find for the 65742 area are satellite things like SuddenLink and EarthLink and I can't even tell if those are real or not.