That's a good point but Monero is a currency, not a treasure, so I think, that won't work. Who needs XMR when it's hard to convert it into fiat or pay for services with it?
There are services that accept XMR, either only XMR, or multiple cryptocurrencies and XMR among them. So, who would need XMR in this case? Someone who would like to pay for the service and maintain their privacy at the highest possible level.
If there are no services to accept it, then it will be limited only to those who will keep it and use it P2P for other types of financial deals (legal & illegal).
In general, it all depends on the demand, I guess.
My points is that more and more services are banning XMR and it's becoming very hard to use it. Many exchanges (including small instant exchanges) remove Monero, many places like Bitrefill cut Monero support. I'm sure that in the near future, there will be more and stricter regulations on Monero, so more and more services will ban it, which will make it very hard to poses and use Monero, which makes me think that it will crash.
Besides the darknet and various markets, there are also many services which do legitimately accept Monero. So nothing will happen to Monero just because a mutli-coin wallet decides to cut support for Monero addresses. Genuinely speaking, it's better to use a dedicated wallet for Monero anyway, so that you can manage the seed phrase properly. (It is of a different format to Bitcoin.)
Yes, besides them there are some services that accept Monero but my point is that, their number is declining. If you could trade XMR on Binance a few months ago, now that's impossible, not only on Binance but on other exchanges too. Since Monero is almost impossible to trace and is a perfect coin for privacy, I'm afraid that governments will push more exchanges and crypto services to cup support to Monero and the number of websites that accept Monero will narrow, that's why I think that it will crash. When I say crash, I don't mean that one XMR will cost one dollar but it will probably worth $50-$100 in the near future instead of $500 and higher price.