Yes, but it would depend on several things that would be specific to your situation.
First, your marginal tax rate on your ordinary income, both federal and, if applicable, state, for the next four years. This matters because if you do nothing else, you can offset $3K of ordinary income per year. Your tax savings would be your total (federal plus state) marginal rate times the $12K.
Second, your capital gains rate could matter. If you choose to realize capital gains (up to $12K) to offset your losses, you'll owe $0 in taxes. If you realized those losses some other time, you might owe capital gains taxes. Your tax savings, if you choose to realize offsetting gains, would be what capital gains you would have paid but didn't.
You can do any mixture of $0 to $12K in capital gains realization, so your actual savings are probably a mixture of the above two.
Third, there are many things that are impacted by AGI, and the capital losses will lower AGI and thus impact these things. In general, there are phase outs and income cutoffs for various things, so lowering your AGI might enable you to take advantage of those things. A lot are tax things, like ACA subsidies, various tax credits and deductions, SS taxation etc. Other things that can be impacted are financial aid (FAFSA is based on AGI and some other tax items) and IRMAA, etc.
The only way to know for sure is to model the various choices in tax software and see what the results are.