so... you invested when bitcoin was worth less, before asic mining, when the difficulty was MUCH lower, and before the halving...
you get the hashpower from the time you invested, perpetually, until you are repaid with your bonus.
spare pyra hashpower (not already allocated to existing deposits) is devoted to crediting the oldest deposits first, and the bitcoin you earn, is after expenses are paid... so as the value of bitcoin drops, the returns are lower, and as it rises, the returns are higher.
you not understanding the details of your investment, does not make pyra a scam.
=squeak=