Couldnt find anything negative about your psu and rtx 3070 online but Azrael1 is right. I dont think you need 1300w you just need one whom holds spikes easily. For instance i have 3080 with old evga 850g2 gold and all work flawlessly.
For future upgrade is good to buy strong psu rumour is that new rtx 40 series will draw around 350-400w
Good to hear thats the same PSU I've got Evga 850G2 Gold Supernova want to run a single Asus Tuf RTX3070Ti from it.