The main things that are slow are loading the app and opening the app, loading the messages, and receiving the messages. On my phone, this is much slower than Telegram, and on my computer, the WhatsApp program doesn't even work have the time -- it just gets stuck in the loading process.
Signal is not as bad, but can still take a minute or two to update everything on my computer. The phone app is better.
Signal is not as bad, but can still take a minute or two to update everything on my computer. The phone app is better.