Not for me. It's always eerily accurate. Maybe you're a really slow driver.
Do you live in a low-traffic area? IME GMaps is least accurate when there's heavy traffic.
I think whoever cracks lane-aware positioning, mapping, and routing could make some big improvements.
But mainly I just want a big button that says "don't make me make unprotected turns across multiple lanes of traffic" - Apple Maps seems less aggressive in that regard than Google Maps, which is why I prefer it.
Exactly, that's the one case where Gmaps gives me bad estimates, as there's something like that for me on my drive to work. The rest of the time, its estimates are very good.
I guess it'd be nice if Google over time determined if you're a faster or slower driver than average and adjusted accordingly.
However Google Maps has an incredibly obnoxious UI pushing me to enable more data collection. The largest text on the search surface is "You're missing out" (by not signing in). If I do sign in, a search for "Home" pops up a modal dialog "Turn on Web and App Activity to search for home and your other personal places". This occurs despite setting an on-device Home location, which GMaps supports.
Apple Maps doesn't ask for sign-in, and a search for "home" uses the location stored on-device. Privacy is why I prefer Apple Maps.