Sure, you make some valid points about the limitations of virtual training. But let's not forget that it's not all about replicating the exact experience of climbing a real hill. Sometimes, it's about building a solid foundation of strength, endurance, and technique that can then be applied to real-world situations.
Take my own experience, for example. I started out using virtual training to build up my stamina and get a feel for different types of terrain. And while I'll be the first to admit that it's not the same as the real thing, it did help me build up the confidence and skills I needed to tackle real hills with more ease.
As for those reported FTP gains, I've definitely seen improvements in my own cycling performance since incorporating virtual training into my routine. Of course, it's not all down to the training itself - a lot of it has to do with proper nutrition, rest, and recovery. But I do believe that virtual training can be a valuable tool for tracking progress and setting achievable goals.
Now, I'm not saying that virtual training is a replacement for real-world experience. Far from it. But I do think it has its place in a well-rounded cycling routine. And who knows - maybe one day, virtual training will be advanced enough to replicate the full experience of climbing a real hill. But until then, I'll continue to enjoy the benefits it has to offer, both on and off the road.