I know that calculating the digits of Pi is something very specific and probably irrelevant to the real practical problems, but somehow it feels appropriate to quickly test the performance of Wolfram Mathematica, especially if the machine is actually called Raspberry Pi :)

So, here is the log of running AbsoluteTiming[N[Pi,10^6];] on a Raspberry Pi with different versions of Wolfram Mathematica, from which it is clear that 11.3, 12.1.1 and 12.2.0 give approximately the same timings, but 12.3.1 is substantially worse.

$ math11
Wolfram Language 11.3.0 Engine for Linux ARM (32-bit)
Copyright 1988-2018 Wolfram Research, Inc.

In[1]:= AbsoluteTiming[N[Pi,10^6];]
Out[1]= {2.03026, Null}

--------------------------------------------------------

$ math12.1
Mathematica 12.1.1 Kernel for Linux ARM (32-bit)
Copyright 1988-2020 Wolfram Research, Inc.

In[1]:= AbsoluteTiming[N[Pi,10^6];]           
Out[1]= {2.08772, Null}

--------------------------------------------------------
$ math12.2
Mathematica 12.2.0 Kernel for Linux ARM (32-bit)
Copyright 1988-2021 Wolfram Research, Inc.

In[1]:= AbsoluteTiming[N[Pi,10^6];]
Out[1]= {3.25156, Null}

--------------------------------------------------------
$ math
Mathematica 12.3.1 Kernel for Linux ARM (32-bit)
Copyright 1988-2021 Wolfram Research, Inc.

In[1]:= AbsoluteTiming[N[Pi,10^6];]
Out[1]= {7.66692, Null}