I’m at 60,000 miles with my 2016 Toyota Avalon, I’ll change the coolant at 100,000 miles with genuine Toyota pink and call it a day until 150,000 miles. All I ever do is a simple drain and fill. No issues ever.
Drove a Lexus LS460 to 179,000 miles before trading it in...coolant changes at 100,000 and 150,000. Never an issue. Water pump never failed...and I was waiting for it too...figured I’d wait to change the serpentine belt until it did. It never did so I ended up changing the serpentine belt at 120,000 miles.
Honestly, Toyota’s are easy on coolant because the engines are built so well that they don’t leak often. Great gaskets, great sealing. No low coolant levels and air/acid situations. No overheating engines, misfires and generally poor running vehicles. You don’t see the head gasket failures you might see on some other cars on occasion. Makes for an easier life on all their fluids.