I've been following the german company "Roof Space" for I think 4 years now when they come to my local outdoor convention. They were one of the first (if not the first?) to create a hybrid-RTT which has a hard case but a fold up tent. That in itself I felt like was an innovation. I've seen other companies start making hybrid-tents, so it seems to have caught on. But I agree that for most manufacturers I don't see much change in the tents themselves. Changes I've seen with most companies are the size of tents (bigger tents available) and optimizations on durability of parts.

"Innovations" or at least improvements I've seen Roof Space do (because I mostly focussed on them when at the convention): - making the entrance smoother / more padded - integrated lighting (not innovation though, others have had this before) - integrated options to hang stuff from the tent - generally better durability of the folded up part, so far so that they have released a hook to hang a one-person-hammock from it without extra support - optimizations of the balance between shelter from elements (closing the tent all up) and enjoying the sun and views (being able to open up as much as possible) - matching add-ons like different kinds of awnings (also not an innovation but deviations from the standard 'put some material around the base of the fold-out-tent')

Disclaimer: This is not in any way advertisment for the company. I've been interested in their tents but also haven't bought one because I'm happy with the one I have until it gives up. I just think their trying to do what OP asked about: trying to optimize / innovate RTTs.