Second clause typically contains ほうがいい / ほうがましだ / たい etc.
The grammar pattern くらいなら expresses that a certain action or situation is so undesirable that the speaker would rather do something else – often something extreme or normally unpleasant – than allow it to happen. It conveys a strong sense of rejection toward the first option.
The structure is: [undesirable action] + くらいなら + [preferable alternative]
The alternative presented in the second clause is typically something drastic, difficult, or otherwise not ideal, but the speaker considers it still better than the first option. This makes the expression inherently emphatic and emotional.
The second clause often uses ほうがいい or ほうがましだ ("would be better" / "would still be preferable") to explicitly state the preferred alternative.
While より is a neutral comparison ("A is better than B"), くらいなら carries a strong negative judgment about the first option. It implies "if things are going to be that bad, then I'd rather…"