Not really, collectibles are the last thing that will go south.
Collectibles aren’t liquid “assets”. They don’t appear on a balance sheet, they can’t be used as collateral and the majority of people holding significant, rare or more desirable Pokemon cards aren’t dummies or flippers going beyond their means… anymore. We’ve spent the last 3 years watching the collector base absorb all the wotc holos which end up on the open market after a huge surge of capital and supply from 2016-2018.
It’s hard to sell collectables. It could get bad for some people, really bad and they might sell off cards but the Rudys and Scotts of the world will be there waiting to scoop up said collections.
Interest in Pokemon is growing exponentially. Trading cards as a market/investment vehicle are growing. You’ve got nothing to worry about as long as you have the stomach for risk and don’t spend beyond your means.
If Pokemon tanks it won’t be soon, it will be in a few years IF collectors leave the hobby en masse and prices plateau. Even then the “low” that might come would probably still be much higher than the prices we see today.