I think for me it had mostly been a matter of what I was used to rather than what was being offered. After all using SimpleMU (for example) for 10+ years I had a hell of a time at some point to switch to even another client let alone play exclusively over the web.
But here is the thing. Why is that an issue? As far as I'm concerned the 'need' for the hobby to move to web-based clients is in order to attract new players who might find the dedicated MU* clients intimidating or off-putting.
Are there games out there which need to be played from a browser because of radical new interface elements or features telnet can't handle?
If not we can have the best of both worlds. Traditional clients for the oldbies and flashy, friendly web browsers for the hip newbies.
Do people still say hip? Is that a thing? I am not hip.