New ISP, finally:
https://www.waveform.com/tools/bufferbloat?test-id=c087da43-a0e0-4165-9c39-7a1b72cbda5f -- benched on my laptop over wifi while it was in power saving mode. Wired is 100-200Mbps faster and a few ms less jitter.
Only broadband option in my area until this year was a giant cable oligopoly (one option is considered a sufficiently competitive market by the FCC) which provided poor and steadily declining service quality while simultaneously doubling in price over the last decade, with no increase to upload bandwidth. Recently I was paying over $100 a month for a 500/20 connection that was almost unusable during wet weather. I had reported problems when I first bought this property, but since they only send people out on clear, dry, days, they dismissed my concerns, only for my modem to report 1-2 million uncorrectable errors a day the next time the weather was less than ideal.
New fiber setup is 500/500 symmetric for half the price, half the latency, and far fewer annoyances. Still twenty years behind some places, but it's the best I can hope for in the middle-income suburbs of a rust belt city where most infrastructure hasn't been adequately maintained in 30 years.