You likely don't need to buy multiple devices. I log in from random countries/VPNs all the time and never have issues, but I do have 2fa enabled. If your account only has a password and there was a suspicious sign in attempt, it's reasonable for them to ask for additional verification somehow because you could be a victim of a credential stuffing attack. It's hard for companies to win here. Either people complain about their accounts getting randomly locked because they were on vacation in Romania and tried signing in on a new device, or the companies get grilled by the media for "failing to proactively protect their users' data" or whatever.