1: International SMS isn't free (US-centric viewpoint, what's the situation in other countries?).
2: No character limit. Which is bypassed with MMS. Which introduces its own limitations when sharing media (reduced resolution/quality of video and images, for example).
3: Potentially, depending on the particular client, not tied to your phone number in a way that others can access (that is, as a fellow user you don't know that my number is 555-555-5555). This can be gotten around by using something like Google Voice, which then loses the MMS feature (have they added that in yet?).
4+: Probably other reasons that I can't think of at the moment.
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It just occurred to me that by "people" you meant the companies that kik is apparently courting with this. They'd want to use this because their users use kik. It's one more interface for customers to interact with them, on a moderately popular chat network.
I believe it's free within most countries. What's not free is across most nation boundaries (particularly non-adjacent nations). It's mostly because you're dealing with the interaction of several different networks. Also, if a company has a lock on its customers, it'll charge them what it wants to charge them.
Other problems with SMS: Message order isn't guaranteed. Message delivery isn't guaranteed. You receive no notice what state a message is in (in transit, delivered, viewed). It's an unreliable medium tied directly to your phone (short using a service like Google Voice) and only to your phone (ok, less true these days, at least in the Apple ecosystem, where I can see and send SMS messages through my Mac if my phone is on the same wifi network). Still requires the presence of my phone in that last example.
These are pretty valid. I guess none of those things are important enough to me, except message delivery guarantee. The thing is, I've never had it fail. And if it did, I didn't notice, so no harm, no foul.
I use Telegram over straight up SMS for many reasons. Group chats that aren't terrible, quick image/gif sharing, stickers (might be useless to you if you're not a furry, lol), bots in those group chats are incredibly useful, secret chats are awesome for my paranoid minded friends that need to talk about illegal stuff with me, and most importantly, I can use the Telegram client on every single one of my devices, so I always have access to my social circle if I have an internet connection.
These benefits may not be as great for someone who has a twitter or Facebook account, but as I don't, telegram is the easiest way for me to talk to all of my friends.
1: International SMS isn't free (US-centric viewpoint, what's the situation in other countries?).
2: No character limit. Which is bypassed with MMS. Which introduces its own limitations when sharing media (reduced resolution/quality of video and images, for example).
3: Potentially, depending on the particular client, not tied to your phone number in a way that others can access (that is, as a fellow user you don't know that my number is 555-555-5555). This can be gotten around by using something like Google Voice, which then loses the MMS feature (have they added that in yet?).
4+: Probably other reasons that I can't think of at the moment.
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It just occurred to me that by "people" you meant the companies that kik is apparently courting with this. They'd want to use this because their users use kik. It's one more interface for customers to interact with them, on a moderately popular chat network.