Not many messaging apps can be used on a smartwatch. Usually only SMS and other applications support direct message replies from notifications. Telegram does offer this application to some clocks and others I rarely see it suggested for use on clocks.
Recently Meta has released a WhatsApp app for Wear OS watches. Making Wear OS the first smartwatch to support these apps natively. Use is simple, after installation, WhatsApp will ask for an 8-digit code that appears on the WhatsApp application on the phone.
WhatsApp on wear OS is simple where messages can be read with simple scrolling. Responding to messages is by voice message or keyboard and there will also be an Open on phone option to continue the traditional style messaging experience.
WhatsApp Group can also be seen at this hour with the list of participants displayed at the bottom. Finally, it comes with support for two tiles for contacts and another for quick voice messages. For now this WhatsApp is still in open beta testing and you can download it directly from the Play Store.