I remember being a 13yo kid sitting on IRC doing exactly this for fun years ago back when IP addresses were cheap and easy to come by. But spoofing military IPs in the traceroute was more fun.
If a 13 year old was using irc regularly in 2022 I would be concerned for them. Not thata 13 year old shouldn't use irc but I would wonder how they found that destination, especially given the countless other sinks for internet denizens
Free software development and chat still largely happens over IRC: witness irc.gnome.org and libera chat.
As a 13 year old, if I had access to internet instead of buying Slackware floppies from local software "pirates" (they also had all the DOS stuff like Wordperfect and games), I'd probably be hanging around IRC.
I don't think there was much to be concerned about me back then.
I _think_ that if you know the real source and real destination of an ICMP message, you can just forge back a message with an arbitrary TTL exceeded message, from any "I'm IP address xxx" address. Those can come from a lot of rando IPs because the intent of them is just "at this hop, the TTL ran out", and the hops the original sender wouldn't know anyway. A lot of fake hops would be essentially impossible if you examined the real BGP routes and stuff, but verifying that in real time sounds hard enough that I bet nobody bothers.
I'd have to do a lot more research and testing to verify though, not something I've played with in practice, and obviously my terminology isn't even right above, so take it for what it's worth.