Indeed Raspberry PI Ltd (formerly Raspberry PI Trading Ltd) paid no tax on its profits in 2020 (the most recent filing year) but not because its a charity - which it isn't - rather because they got tax deductions for R&D. I strongly suspect that these deductions would be available to any other firm that spent the same amount on R&D.
And of course they did pay a significant amount of VAT (sales taxes) on these boards.
In short the tax insinuation bit of this is very likely completely unjustified.
Edit: I've read the rest of the post this comment quotes from (on the IPFire Forum) - it goes on to accuse RPi of tax evasion (i.e illegality) - seemingly because they are annoyed that they don't make it easy to run their software on it. This is not an 'interesting perspective'.