I use Citymapper for this; have for years (https://citymapper.com/). It does exactly what you're asking for. I too am surprised that Google hasn't eaten their lunch by baking this into Google Maps.
Oh, I hadn’t seen that! But hmm, it doesn’t seem to have jump bikes/scooters, Lyft scooters, bird, or lime in the scooters section, and again there’s no multi-mode.. it just shows walking/biking/Uber/public transit but not a combination of them. It does have a jet pack option which is nice and forward thinking! :)
I suspect that curating accurate transit data is a lot of boring, never ending work, and on the other hand, Google don't think they will have big enough money there(without building something like UBER, not their style), so they don't bother.
