Dying, no. Shrinking, yes. The two are not the same thing.
The check itself is in decline. Fewer checks get written every year, and that will not reverse. If your only product is “hand me a paper check and I give you cash,” your volume drops a little every year and you should plan for that.
But look at who walks into a check casher and why. It is the person paid by paper check who cannot wait three days for a bank hold. It is the day laborer, the small contractor, the gig worker, the person with no bank account or one he does not trust. That customer did not go away. The banks still do not want him, and the apps have not fully reached him. Someone has to serve that gap, and the check casher already has the storefront, the license, and the trust.
So the smart operators stopped being check cashers years ago. They are MSBs that happen to cash checks. The check brings the customer in. Bill pay, money transfer, prepaid cards, small loans, and in some states crypto, keep him coming back. The check is the lead. The rest is the business.
What is actually dying is the single-service, single-location, cash-only shop with no compliance program. Banks are closing those accounts, regulators are tightening, and the owner has no second product. That shop was dying before checks declined.
My answer: if you are buying one, you are not buying a check-cashing business. You are buying a licensed MSB with a walk-in customer base the banks ignore. Price it that way, run it that way, and it has years left. Treat it as a check shop and it will shrink exactly as fast as the checks do.