I'm not sure why you think this but it is very incorrect. I can't speak for your Toyota, but most car headlight assembly's absolutely allow for replacing the bulbs inside them.
Your dealership may not tell you this because they're incentivized to sell you that 2k housing, but do some research and you will almost certainly find that you can replace the bulb for $50 or less.
> most car headlight assembly's absolutely allow for replacing the bulbs inside them.
Yes, because the vast majority of OEM head lamps are still not LEDs.
You must be thinking about HIDs.
OEM LED housings almost universally have no user serviceable access for their LED components, nor do they have standardized "bulbs". You can find plenty of videos of people 'opening' LED headlamps on YouTube [0][1] -- it is a destructive process. The housings are sonically welded with the LED components inside, and the only way in is by cutting them open.
While there are retrofit bulbs for halogen housing (made in the shape of halogen bulbs) for the aftermarket, no OEMs use these for factory LED lighting.
But you don't have to take my word for it:
1. Go look up any vehicle with factory LEDs on the websites of Sylvania, Philips, Hella, etc. You will find that they do not list bulbs for those lamps.
2. Read the owners manual or parts diagram for any vehicle with factory LEDs -- you won't find bulbs in the parts diagrams, and the owners manuals will explain that the housing must be replaced.
Your dealership may not tell you this because they're incentivized to sell you that 2k housing, but do some research and you will almost certainly find that you can replace the bulb for $50 or less.