The dealer is correct.

New car sales were experiencing a prolonged period of decline long before Covid-19 brought production lines to a juddering halt in the spring of 2020. A global shortage of semiconductors in 2021 is also limiting the supply of new vehicles, which means there is a national shortage of new and nearly new cars in the UK.

There will be new cars in 2022. But the supply chain will struggle to meet demand until the shortage of semiconductors is dealt with. Sadly, the solution is building new semiconductor sites and this will take a very long time. It could easily be 2023 until things have returned to normal.