Hmmm,
I suppose general thinking on certain types of MTB geometry has ” Moved On” a bit, but we’re not talking staggering seismic shifts in thinking really; a couple of degrees in head angle, maybe +/-10mm of top tube in some cases, but I doubt your bike is actually as “Dated” as you think it is, plus it all comes down to the reality of using it, is it actually un-ridable? or are you still enjoying riding it?
I’d suggest keeping it personally as it’s gotten you this far, see if it can make it to the 10 year mark… By which point it will owe you even less.
A decade of use at ~£150 a year is a relative bargain…
Shiney new things bring their own problems when they fail to live up to the hype/expectations and they tend to dent the bank balance, the money you don’t spend on a new frame could probably cover a couple of alpine trips, or carry in clocking up some interest ready for the next purchase in a couple of years…