Actually I think the future of Compact is ICE, Hybrid and EV's. Weight is an issue for efficient ICE, becoming a significant issue for EV's.I agree that the future is "Compact" for ICE vehicles.
I never really saw the Defender as a tow vehicle -- it's nice that it CAN tow, but I agree with you that if I needed to tow often I would be looking outside of JLR for that rig. .......
My 2011 LR4 has been a great tow vehicles over the years. The 5.0V8 is plenty of power. The rear liftgate/dropgate wasn't an issue for access even with a TT attached. I replaced the factory tow hitch with the Rhino hitch (even JLR couldn't confidently give me towing limits). After several years of camping/towing, we had zero issues. We did discover the limits of wheelbase as the LR4 is relatively short at 114" and that travel trailer tongue weight is under-spec'd by manufacturers. They spec dry weight while the normal weight is wet, with propane, water, etc. The low JLR tongue capability becomes an issue relatively quickly.
The tow vehicle wheelbase becomes an issue for TT's above roughly 21-24'. Your suggestion on TT sector adopting more sophisticated frame/suspension design principles is interesting.
Over the years we have gone from tents to 19' to 23.75' TT's. Sometimes moving up from 18' TT's, back to pop-ups, then to tents, then to 19' TT and recently 23.75' TT. In all cases the TV became the exploratory vehicle for day trips while the TT was "base". A slight case of two-foot-itis over 40 years but I'm pretty sure we are done with those changes.
JLR has the design capability to support towing. Their product line choices mostly don't support a TT. The factory doesn't even offer towing mirrors. Where did I have to go for towing mirrors? Well Australia!
So full circle. LR's direction is smaller lighter models as they move to hybrid and EV's. You see that even with the RR that has lost a 1000 lbs and become less tow friendly. From a CAFE perspective JLR lacks a segment of vehicles that supports higher GVWR's. Maybe the move to add the D80 product line will enable them to add a higher GVWR product line.