should i download ICQ?

According to Wikipedia...

"According to a Novaya Gazeta
article published in May 2018, Russian intelligence agencies had access
to online reading of ICQ users' correspondence during crime
investigations. The article examined 34 sentences of Russian courts,
during the investigation of which the evidence of the defendants' guilt
was obtained by reading correspondence on a PC or mobile devices. Of the
fourteen cases in which ICQ was involved, in six cases the capturing of
information occurred before the seizure of the device. Because the
rival service Telegram blocks all access for the agencies, the Advisor of the Russian President, Herman Klimenko, recommended to use ICQ instead"

So, the Russians are saying "Don't use Telegram! Use ICQ instead so we can better spy on you!" If you're Russian or someone the Russians would be interested in, you should probably avoid this. It might be ok if you're international, but you'll always have Russia's metaphorical noose hanging over your neck

Also "In 2023, an investigation by Brazilian news outlet Núcleo Jornalismo found that ICQ was used to freely share child pornography due to lax moderation policies". Excuse me, WHAT THE FUCK!?!?!?!

Having someone recommend ICQ because they don't have an easy in to Telegram doesn't make Telegram safe, maybe not as dangerous, but not safe.  I'd be interested to try Telegram myself, but more for checking out what's on there, if I wanted to have private conversations I'd move them to XMPP (with OMEMO encryption) or Session messenger.  

My understanding of Telegram is that encrypted messaging is off unless you turn it on and it is never on for group messages.  Maybe that's changed though, I don't know.  Also, as far as I know you can't join without giving them a phone number and using their official app to create an account, so right there that's a problem.  I'd consider doing that with a separate phone number not used for social contacts on a de-Googled phone (if possible) then moving the use of the account to a 3rd party app, but that's not advice that doing so would be 'safe', just something I'd consider.

Definitely check out XMPP.  You've probably used it in in-game chats and other places without knowing it.  It's been around a long time and is what some people consider 'email done right'.  People can't spam you, they can only send a friend invite with a message attached, but that's it.  It's a protocol which is federated, so you'd create an account with a provider like you do for email, or if you wanted to you could even set up your own server.  But the point is that it's not centralised like WhatsApp, Telegram and so on.

Session uses onion routing through Lokinet.  It's super easy to set up, you just download the app and create an account.  What that does is create a public + private key pair, you don't actually have to give it your name or phone number or anything, it just generates an account.  Though you may wish to share your user ID through some other secure messaging system if you want to keep that private.  Or, create an account, send the ID to someone out in the open, then once you've established communication you could create another account and privately send that ID through the first account then burn that first account.  Depends if you want your Session ID to only be known by your contacts or not.

I've heard good things about Matrix, but apparently it's kinda bloated so running a server is more expensive than the likes or XMPP.

I've heard good things about Briar, might be worth a look.

I really encourage XMPP though, how different things would have been had it taken off instead of email!