Understood. We constantly add capacity and expand to new data centers. Recent massive change of IPs was related to major servers upgrade (you might notice performance improvement last couple of months).
We would be happy to buy couple of class C IPv4 networks and bring them with us everywhere, so customers upgrade firewalls once and forever, but this is unrealistic nowadays.
Providing dedicated IP is good idea but there are some challenges with it. We have multiple locations (Liquid Web, Google cloud, AWS and recently added Azure). They are now interchangeable. If we implement dedicated IP within single cloud vendor, it will not stay if that particular cloud goes down or overloaded. And we definitely do not want to stick with a single cloud vendor.