I bought mine outright. I nearly leased, and had I got the quotes I was getting back in 2019 I probably would've. For some reason, back in 2019, the leasing quotes that were floating around made it seem like a no-brainer - it would basically cost ~£17k over the course of 3 years. I couldn't see a way that the car wouldn't have lost that amount in depreciation in that space of time.
When I came to actually looking to buy the car I got quotes from 10 different places, and they were all considerably higher than before. I was told that "the industry was concerned" about their exposure as they already had loads of cars on their books, and at the time Tesla was doing their Tesla thing of changing the prices constantly for no apparent reason. In the course of a couple of months where I was seriously looking the lease quotes often had to get redone because of these price variances.
As it turned out the quotes I was getting in early 2020 made leasing seem unpalatable compared to buying outright, which is what you'd expect when its normal really - i.e. you're getting credit and passing on your exposure to a third party.
In the end I managed to get a M3P just under the wire before it lost the PICG, and before it dropped by £500. It was literally a matter of hours I think, fortunately my car had been put through the OLEV portal in the gap between the mini Budget and changes taking effect. I bought FSD too, which went up by £1000 shortly afterwards.
So I "saved" about £5k on the car compared to buying it now, but that has probably been swallowed up in the hit from the 2021 changes, I would imagine.
My only concern with depreciation really is some sort of cataclysmic event like the overnight £40k price cut on P100D was (RIP to those people who got hit by that). I can't conceive of how that would happen, but at the same time the Performance version is somewhat more exposed if e.g. a Ludicrous 100kW M3P comes out at the current (or near) M3P pricing.