Just for the record to put things in a slight perspective, I still have 2003 (and 2010) on my old Win 7 laptop working quite happily. On my main PC I'm running 2021 on Win 10 which I moved to when my old HDD (Win 8.1) gave up the ghost. The transition/conversion from 2003 to 2021 databases was very simple but a fair bit of work - not much beyond adding PtrSafe to my Declares.
What I really miss, however is integrated Visual Source Safe. I make do with AccessVCS and other tools but they aren't the simple complete solution that VSS was.
Also the IDE in 2021 (indeed from 2010 onwards) is unnecessarily more complicated than 2003, albeit liveable with once I got used to it.
The one advantage I really like with 2021 is purely cosmetic - the ability to combine pictures and text on buttons.
And the icing on the cake is that 2003 still has the old style (more coherent) MsgBox - and yes I realise this is a mterer of taste, but I like my message boxes to match my forms.