Well, the senate is an institution controlled by the minority by design, that's what have lead to this super-conservative court in the first place.
Probably the biggest regret dems will have in 20-22 was not giving Hawaii and/or DC statehood.
They need to level the playing field in the senate, otherwise, it will always be an uphill battle to control it.
Republicans will take back what is supposed to be their senate seat in WV this election, dems may squeek out one last term in Ohio and Montana, but after that, these states are gone.
Where can dems make up for it? Wisconsin and Maine, basically, can't afford to lose these states anymore.
They need more states they can win in.