Another reason I would say you don’t see domestic is because Ford/GMC/Chevy all hasn’t updated their platform In quite a while here in the US.
You’ll see the ranger replica much more commonly in Australia where it has been for sometime. And now that GMC and Chevy have the Colorado Canyon updated, you are seeing them much much more. Where as Tacoma’s have been selling since the late 90’s and keeping a somewhat updated platform.
Give it a few years and the domestic mid size scene should be coming up on the Tacoma’s.
If you want to see some really great Colorado’s and a great Ranger, check out Peak Suspension. They have been a front runner for these trucks and overlanding.
To answer your question about the aftermarket scene for the Colorado canyon; No, the aftermarket parts for these trucks is all there and pretty much everything you need. Many of the fab shops make universal bedracks, there are plenty of bumps, Baja kits has long travel suspension(the suspension is the one area I wish had more options), there are now regearing options.
And as to reliability, I don’t think that’s much of an argument anymore for vehicles in general. Especially for companies like Toyota, Chevy, etc. because everything is monitored and controlled by computers now. Plus, there are tons of old Chevy S10’s above 200k miles. Yeah they don’t hold their value like a Tacoma, but why are you buying a vehicle if you are thinking about selling it already?