for GPUs profits are low because BTC is bear right now and there are too many GPU mega farms and too many individual farmers.

Profits will be low for Asics for the same reason.

z9 and a9 have been on sale for some time now so you can expect 35-50% increase in difficulty with in 3 months extending your ROI. consider also that they are easier to deploy.

prices are so low right now I would recommend buying crypto instead of mining.