An involved solution can be to set a Matrix bridge up for most services, including WhatsApp.
The downside are:
1. You have to host your Matrix server, so not everybody will be happy about it, or able to do so;
2. This relies on reverse-engineering the whatsApp web API, and is against WhatsApp TOS, you might get banned
3. You need another device with WhatsApp installed (an old android phone or a VM works fine).
Personally, this is the main reason why I refuse to use any of these proprietary apps, and I make this clear to my friends.
On the upside, if you go that route, you can go the extra mile and bridge facebook messenger, discord, telegram, and others to your Matrix account, and control everything on the go from a single app. I'm planning to work on push notifications for the Linux phone platform :)