IP Geolocation Accuracy Woes

Hey everyone, hoping for some insights here. We recently launched our new SaaS, which is all about localized service discovery, and it's absolutely critical for our users to see relevant local businesses. We also rely heavily on it for accurate content localization. The big problem we're running into is significant IP geolocation accuracy issues. Many of our users are incorrectly mapped, or they show up in default ISP locations, which really impacts their user experience, our service matching, and our geo-targeting efforts. This unreliable location data is a real headache. Initially, we started with a popular free IP geolocation API, but the inaccuracies were too frequent. So, we switched to a paid service, something like MaxMind GeoLite2, hoping for much better supposed accuracy. We even tried combining IP data with browser navigator.geolocation whenever it was available and permitted by the user, and we've implemented some basic proxy and VPN detection logic to try and filter out the noise. However, even with the paid services, we're still seeing noticeable errors, especially for mobile users or those who might be using residential proxies or VPNs. Browser geolocation is often denied or simply not available, and sometimes it's even too precise when we only really need city-level data. The VPN detection part feels like a constant cat-and-mouse game, and it frequently flags legitimate users, which is not ideal. The core issue we're facing is consistently getting reliable city-level location data without being overly intrusive or constantly getting spoofed. So, I'm really keen to know, what are the industry best practices for achieving high IP geolocation accuracy for city or region targeting? Are there specific services or perhaps combinations of services that yield significantly better results than just relying on one? Any practical tips for dealing with residential proxies or the variations you see with mobile IPs? And more broadly, how do larger platforms effectively handle this challenge?