FD
I think if you ask pilots who have full TKS (not many around, yet) and who have experience of traditional twins with rubber boots with bicycle patches stuck all over them
they will tell you that TKS is a LOT better than a get out of jail card. It is an anti-ice system, preventing ice forming in the first place and is an order of magnitude more effective than rubber boots.
I have a mere TKS prop and the resulting spray completely prevents ice forming on the front window.
No system is going to make it OK to fly around in icing conditions indefinitely, because ice will build up somewhere on the airframe, without a limit.
Re the pitot tube comment, I said "airframe". I don't think there is any physical mechanism to get ice BUILDING UP on an airframe which is flying through air whose temperature is above 0C (i.e. the airframe temperature will be above 0C too). A pitot tube is a different scenario because bits of ice can get stuck up the hole and more or less stay there; in any case you don't want ANY blockage in there at all.