If they have added 83 assets to their exchange for trade and they now have 139 tradeable assets in total then this was really a massive growth in the last year as the number more than doubled in this short period of time. As others already mentioned in here they kind of had to do that and they even added some meme coins to their portfolio and i would guess that they did not want to add such sh*t coins but they had such a high volume at times that they just could not miss out on those trading fees.
This is what people are missing whenever they see a coin get listed at a good place. Those places doesn't have stamp of approval for these coins saying that they are "good", they just look at the trading volume and want to make profit from those coins. It could be as bad as it gets, it could be the worst shitcoin but as long as there is money to be made for Coinbase then they will list it.
This is why I have to say that just because they listed those shitcoins doesn't mean that they are supporting those coins neither. With the addition of staking and all, there is a good chance they might even use your deposits to make a profit as well from staking, while your amount stays the same, they are making extra income from it.