If I HAD to use one, which one would be better? While Whatsapp is owned by Facebook, they have end to end encryption for the messages, while the metadata is not. However, on Telegram, nothing is end to end encrypted unless you use a secret chat which most regular people are most likely not going to use. I have a feeling Whatsapp would be better but I wanted to hear your thoughts.
Telegram. For most stuff, especially public groups, e2ee is vastly overrated.
What matters more is that the Telegram clients are fully open-source and accessible from a more trust worthy 3rd party on F-Droid. With WhatsApp you have basically no idea what the closed client is really doing on your device and you are also stuck with Googles user tracking via the Playstore.
In addition (at least for now), Telegram has a pretty open API, meaning that you can connect to it with alternative clients and bridges easily and without much risk of getting your account banned. Due to this there are many nicely working 3rd party integrations and overall you are much less held hostage by the main provider as in the case of WhatsApp.