I’ve heard people having problems with them for web hosting, but I’m not sure if this applies to their VPS as well.
I am very happy with my VPS in IONOS. I pay the cheapest plan though but i have had virtually no problems with them for 2 and a half years. I recieved a mail once for a downtime but happened at european night so i didn’t even noticed. Otherwise, the dashboard solved any problem i caused.
I only have a very few selfhosted services there due to the limitations of my plan, but they are essential to me and i would recommended you to try it. It’s 1€ + taxes a month, very affordable, but very limited in resources.
I’ve had an IONOS VPS since January and have no complaints. I even rebuilt it at one point. I have a larger VPS for $20/mo.
I’ve used ion for years for web hosting with no issue. Not sure how it would compare