I think at least exotics and old raid gear should be infused. I like having options, the option to either shoot at a bullet sponge with any vanguard rifle or the fatebringer. Or I can shoot it with my gjallarhorn or sleeper simulant. If I had my old gear at 280 I would still be using the new gear. I've always went after the new gear. The more options to fight an enemy the better. I think if raid gear would be infused you should still have to play through the new raid first and collect some kind of shard that's randomly dropped which allows you to infuse the old raid gear(like etheric light). That way you still have to play through the new material to be able to infuse the old gear. By that time you would have already tried many new guns and armor.