I grew up watching reruns of the first series, and have enjoyed various stretches & episodes of the later series, but honestly, it wouldn't be any great tragedy to me if the franchise died a natural death.
I mean, as we've come to learn, the whole premise was an interesting thought experiment, but hugely flawed. Roddenberry in no way 'practiced what he preached' in real life, and space travel is almost certainly complete pie in the sky nonsense from multiple angles. I won't bother going in to the current existential & sustainability threats that will render it unlikely, but there's also this massive problem.
Going somewhat against my own opinion above is the fact that some of the later series drifted in to grittier, more unpleasant directions, and that does seem appropriate for where the world is now. That said, such is not particularly in line with ST's naive optimism that ran through the first few series. It's not on brand, for whatever that's worth.
Other than marketing, finances, and studios recycling absolutely everything they can if it's projected to make money, it seems completely appropriate for some other series to have a say, altho I imagine it being darker and more apocalyptic.
I still love aspects of the earlier series (and books... there were some fine novels), but I just don't care about the franchise continuing on, anymore.