That's right.
It's likely that both of them won't be existing anymore by 10 year but it shall be Shiba Inu that shall be gone first. But for Dogecoin, there might still be a community that will have it alive.
To have these coins as part of your portfolio, it should be the amount that you can afford to lose.
Dogecoin was launched around December 2013, So it's almost 8 years old. 2 years short of your 10-year condition. I can bet anything that Doge will still be there in 2023 December. It's got a community of believers who have been there since 2013 of which it has even grown bigger. Doge has gone through different bullish and bear markets, it has it's own blockchain,
As for SHIBA INU, what is driving it right now is hype. It hasn't tested the bloodbath yet, and it doesn't have its own blockchain. Just an ERC20 token
Long term, I would still bet on Doge but definitely after we have seen the end of the current bull market.