It still will be for as long as many people cannot get and maintain a free bank account that is usable for transferring funds via whatever scheme you envision replacing checks. And the property that checks have, namely that some percentage of them get unwound for various reasons and that percentage varies substantially by customer, is very hard to get rid of. As long as that property exists, access to a bank account that provides that mechanism will be an extension of credit and thus not universally available.
It's possible that a system for instant payment clearance, like FedNow, might reduce the problem of insufficient funds and similar clearance issues. However, that doesn't eliminate the possibility of bad/fraudulent/etc checks, just reduce it.