Yep, as PDC says- we've got a pretty good deal in some respects (though most of europe has 25 years, and other countries within Europe don't have tax/testingfor bikes <250cc etc anyway).
My CX I have regisered as historic just this month actually and got a cheque back with remaining tax credited to me. So that's the 4 vehicles now I don't pay tax on.. No restrictions if using the vehicle for personal use (not commercial). All year riding, as many miles as you want, and pretty much whatever you want to use it for, whether that's commuting or not. The only thing I had to do (though I've done it for other bikes too) was get a certificate (£25) from Honda declaring manufacture was June '81 and not mid Jan '82 (which is when it was registered). Good job I did that in 2020, because it took UK Honda 8 months to finally give me the certificate at which point if I started now I may aswel not bother paying the £25. That said, now I am essentially registered historic a year 'earlier' than I would have been if I didn't get proof of manufacture. So, in my case, for my bike (and yes this is for the UK proceedure), I sent off the V5 logbook with 'vehicle taxation' modified as 'Historic' instead of 'Bicycle', sent off V112 (MOT exemption form), and V10 (Application of tax), as well as the certificate of true manufacture and a cover note to Swansea and all was good. 5th time doing it.
As for insurance, I hate 'classic car/bike' insurance and I strain to the brokers that I don't WANT classic insurance, just because I have an old vehicle. Not that it's a big deal at my age and experience but you don't get NCD for classic insurance.
I save £597 at current table rates that I otherwise would pay for my 4 historic vehicles, including MOT. £295 is tax on a car though, which I've had historic since 2020. It adds up my friends! Pity my next vehicle to be declared historic isn't until 2028.... then the next 2031, then 2032, then 2053 haha.