The problem with packing the court, is there is no logical end to this approach. Biden packs it (well, AOC and Bernie...) and then the next time the country comes to its senses and votes out our socialist president, the pubs pack it some more. Now we're up to what, maybe 23 justices? After that, it gets packed some more, and so forth and so on, until... Until what? What is the ultimate outcome?
Packing the court just screams of a small child who doesn't like the rules, so they flip the board. Or maybe the more mature screaming children just try to change the rules of the game, but they're still not smart enough to realize that the rules can be changed again in the future.