Is there any reason that a competent local garage cannot do standard oil changes on high end cars? I had a Mercedes once and the dealer told me that only a dealer had the parts to do an oil change. I didn’t bother to challenge it at the time but they get five times what a garage gets.I now have a Lexus.
Any garage can do a Lexus.
Ferrarri, Bugatti, Maseratti, or Lamborghini might be better done by a specialist.
Perhaps the rule of thumb might be that if the nameplate ends in “i”, go to a specialist.
Laws have changed. Your owner’s manual & warranty that came with your Lexus should make it clear that as long as you keep maintenance records, you’re covered by warranty.
Conversely, you could go buy the parts from the dealership and do it yourself. Though you’d have to price that out to see if it’s actually cheaper to do it yourself than for them to do it.