Not fully, there are still places a backdoor could be hidden (and that’s disregarding the possibility of backdoors in OpenWRT, which just recently fended off its own supply chain attack), but I’d sure trust it more.
The thing to keep in mind is that the more sophisticated and difficult to detect a backdoor is, the more valuable it is. And therefore, the less likely it is to ever be used against a normal person. So getting rid of blatantly buggy and insecure software, which TP-Link unfortunately has a bit of a reputation for, goes a long way. And not to pick on TP-Link, evidence suggests many/most home routers are riddled with vulnerabilities.
Hardware backdoors are also possible in the silicon, and are probably some of the most dangerous. Fortunately also probably some of the most sophisticated and difficult to introduce.