For me, calls and texts are a big part of why I have a phone.
If money is tight, and you are only concerned with keeping in touch with a couple folks, and they’re willing to switch to WhatsApp for a week or however long you’re gone, sure.
The list of people I’d need to notify, personally and professionally, is just too large... and I’d rather not inconvenience them with having to download the app and use it to talk to me. Not to mention alarm system calls, lawn guy, etc.
For me, if I’m spending thousands on a week long international trip, the extra $40 over a SIM to have my phone work seamlessly is worth it. Plus you’re not having to hunt down the SIM, buy it, change it out & set it up, keep up with your original SIM all week.
If I was going for a month or more, I’d likely get a SIM or a local phone and forward calls. Thankfully there are options that fit everyone’s needs.