Alternatives to Skype for international calling?

I hate Google but Google voice is how I used to make international calls

Yolla seems to have similar prices. I bought some credit with them. I haven't needed to use it yet, so I cannot vouch for the call quality. Unlike others, their credit doesn't expire after a certain period. You can also get a good deal by searching for discount codes before buying credit.

At least here in the US, lots of mobile phone plans have free or cheap international calls, depending on the countries involved. Example. Some home landline plans also have that. So far that has been enough for me on the few occasions when I've wanted to make an international call. If more frequent, I'd use a VOIP provider, maybe Twilio (I'm sure there are others too, but I know Twilio supports this and has a decent API).

VOIP providers will often also sell you inbound phone numbers in the destination country, if you want the other person to be able to call you from their landline without it getting rung up as an international call for them. Those aren't always so cheap, but there are obvious use cases.

Zoom phone, google voice

I use a SIP phone service now (zadarma.com). They have an app for Android, and it also works with the SIP clients on my Linux desktop. Can't give a longtime review of them yet, as i am a Skype "victim" too, but so far so good.

I think there is another messenger called Viber that can call landlines, but it looked a little sketchy to me.

Skype for business is still supported

Google voice works fine for me. Requires a payment but the rates are very cheap.

Check out Jmp.chat

It's not directly what you're looking for, but it does offer VOIP via XMPP. Voice calls are crazy cheap, like 0.1¢/min, or something (I forget, it's so silly cheap I just don't care).

You can use it stand-alone, or port your phone number in and now everything (calls/sms) go through XMPP. This is how I found them, as a solution to crappy SMS being tied to a physical device. Now my (crappy) SMS is on any XMPP client I use - phone, laptop, desktop, iPad, etc. And all calls are VOIP from any device, so long as the client supports it. I don't think there's a Windows client that yet supports voice (Gajim is the go-to for XMPP on Windows), but there's: Android (Cheogram), Linux (Gajim) and iOS (Snikket).

I used to use an app called WeTalk ages ago when I was calling to countries that blocked Skype.

It was kinda janky and not free but dirt cheap(1.5-2¢/minute.

Haven’t used it in years though