Meh, Toyota's heated steering wheel is MEH anyway. I tried it out in a loaner Rav4 I had once, and it only heated the 9 and 3 'o' clock positions, rather than the entire wheel. I think that's the case across Toyota's lineup. I felt it was something I could do without.
Some of the features the Platinum has, though, like the 10-way driver's seat with memory, and the power tilt/telescope steering wheel (also with memory), the auto dual-zone climate control, the cooled seats, etc. I could see myself wanting those. I wonder if I could straight trade my low mileage Tundra SR5 for a same year higher mileage Tundra Platinum? (or a 2019 so it has smartkey and Android Auto) Probably not, eh? Not sure I want to do that, either. I know exactly how my truck has been treated.