Almost every tool on this list connects a bot, not an account
Before comparing features, it is worth understanding the one architectural decision that separates these products. Telegram exposes two very different interfaces. The Bot API is free, open and easy to integrate — which is why every general helpdesk, CRM and omnichannel inbox uses it. The user API is what Telegram clients themselves use, and it is what lets a piece of software act on behalf of a real account.
Telegram places hard limits on bots, and no vendor can engineer around them. A bot cannot send the first message to a user — the person has to start the bot. A bot added to a group cannot read anything sent before it joined. In groups, bots run with privacy mode enabled by default, so they receive only commands and messages that reply to them directly.
The practical result is that a bot-based integration sees a small, opt-in slice of your Telegram activity. If your customers write to a person — which is how the overwhelming majority of Telegram business is conducted — the helpdesk never sees those conversations, cannot follow up on them, and cannot report on them.