Weeeeeeeeeeeeeeeeeeeeeell... yes, but it's closer than you might think.
Let's assume you're an A driver regularly finishing top ten in your nation in GTWS and Exhibition seasons, and hitting gold at every time trial...
There's been eight GTWS seasons that award prize money (I think... I think it came in with the official 2023 season from May to July), and you could notionally score just over 12m credits each time. That's 72m credits (actually a bit more).
Additionally there's been 70ish Online Time Trials, each awarding 2m credits, plus another four special Time Trials that I think awarded the same, and some regional special Time Trials which I won't include but will give more to some users in the USA. Call it 75 at 2m apiece, for 150m credits.
There's been a handful of special races for live events, as well as "guess the winner" events that account for about another 15m cash and car between them.
I'm earning about 1.5m a month from tickets, so with 25 months now that's 37.5m, as well as picking up about 2m of car prizes each month. Assuming half are new and half are sold, that's about 0.5m per month (12.5m) income and 1m a month (25m) saved in not having to buy cars.
There's also a mild reduction in the overall cost of the cars, by about 30m, if you gold all the single-player stuff like licences (MP4/4 notably) and the extra menus (D-Type particularly). I don't recall the current all-car cost, but it's over a half billion now.
So all in we're looking at:
Cost: 500m (total) - 30m (one-time prizes) - 25m (ticket prizes) = 445m
Income: 20m (World Circuits x1) + 50m (CE) + (whatever licences + missions pay; 25m?) + 150m (OTTS) + 72m (GTWS) + 50m (tickets) +15m (Live event tie-ins) = 382m
Difference: -63m
By the end of the next year, if there's no very expensive cars added and we get more than two GTWS seasons, it might actually tip over to a profit for the diligent and high-ranked player.
Not for the rest of us of course, though a reasonable driver can still get half that from OTTS and GTWS (I got 6m from doing ONE race in GT2 League a season or so ago), so maybe 260m in total.