Soldato
You have graphic card that is older than Ryzen 5 2600 that is still running fine, you dont need to buy ATX 3.0 PSU anytime soon unless your graphic card go pop and you go buy RTX 4000 series or Radeon 7000 series GPU that use 12VHPWR connector then you will need to buy ATX 3.0 PSU to power it. If both RTX 4000 series and Radeon 7000 series will supplied 12VHPWR adapter then that will be great. But when you use it with your EVGA & Superflower 550W PSUs and try to run very demand new ray tracing game, if either your old PSUs shutdown instantly to protect it from power spike or power surge prevent damage to your GPU, HDD, SSD, RAM and motherboard. Your current PSUs would not handle it so you will definitely need to buy ATX 3.0 PSU.
I know what will happen because I saw it with my friend in 2008 when I helped him to installed new motherboard, AMD Athlon 64 X2 6000+ and Geforce 8600 GTS, he wanted to played GTA IV after he found out his old Voodoo 5 5500 cant run GTA IV. Replaced old Socket A motherboard, AMD Athlon 1200 and 3dfx Voodoo 5 5500 AGP I helped him build it back in 2001. But we not thought about PSU, his old Q-Tec 450W still worked since bought it in 2001 used with Voodoo 5 5500 AGP. I assumed it would able to run it fine with Geforce 8600 GTS with supplied PCI Express power adapter so his PC booted and reached desktop fine, he was able to browsed internet for hours fine and able to run GTA IV fine but after 5 mins his PC shutdown instantly, it happened to every 3D games too he tried ran shutdown instantly after 5 mins. I realised his ancient Q-Tec 450W ATX 1.0 PSU do not have enough 12V power required to run Geforce 8600 GTS stable, I told him he will need a new PSU, I ordered Antec Truepower New 550W PSU with quad 12V rails, he installed it and GTA IV ran great without PC shutdown instantly.
I remembered my first AT 250W PSU in 1996 but cant remembered brand, it ran fine lasted for 4 years until it went pop in 2000. I asked my dad for a new PSU while he was home for lunch break. After work in Glasgow he went to Infiniti Computers in Cook Street asked assistant for new PSU and he bought Q-Tec 300W ATX 1.0 PSU for about £15, it worked fine but it was hot and loud then in 2003 I decided to cleaned my PC removed all dusts and found PSU has full of dusts inside but I would not risked opened it to cleaned dusts off so I dumped it and ordered Antec Truepower 430W for £75.74 after read reviews, PSU went fine for 2 years then I sold it and bought Antec Truepower 2.0 550W ATX 2.0 with dual 12V rails and 6 pin PCI Express in 2005 for about £79, PSU worked fine for 2 years until it went pop in 2007 then I ordered Antec NeoPower 550W Modular PSU ATX 2.2 with triple 12V rails for about £85. PSU worked fine, in 2010 I gave it to my sister and ordered OCZ Z Series 850W for my PC then in 2011 she told me her Antec NeoPower 550W Modular PSU went pop while browsed internet. I gave her my 1 year old OCZ Z Series 850W and ordered £147.58 Corsair AX850 Gold for my PC, AX850 worked fine until it went pop in 2015 and I ordered Corsair AX860 Platnium which my PC run fine for 7 years now. My sister old PC is in other room, 12 years old OCZ Z Series 850W PSU was surprised still worked fine, been tested with RTX 2080 2 years ago ran ray tracing games on old AMD Phenom II X4 940.
I dont know why you would argue otherwise.
