Nah - keeping in touch on social media is an on and off thing. Take me and Laeserin for instance (can't @-ping on #Rabbit bleh). I've been following her since almost as long since joining Nostr; but we don't talk regularily - yet, we cross paths once in a while and she even pinged me about a german nostr meetup; we do "know" each other, in that sense. Likewise, I used to interact a lot with a guy going by Akito whom I haven't seen in forever - they might have left Nostr already. People come and people go - kind of the nature of an SNS. Basically, picture a staircase with the label "level of closeness". Not super accurate but:
- Social media: You see people in the pulic, say hi, see them once in a while and talk. They're a familiar face.
- Group chat (i.e. Discord server, Telegram group): You know those people rather well and have turned people that you know from passing by into people that you talk quite frequently now, even "outside the street".
- Direct message (Signal, SimpleX, ...): That person is very much a friend. Sometimes DMs are also temporary and a result of an SNS interaction but not too common. This is what I would consider the highest step on the staircase; you are probably close friends by now.
Again, not super accurate, but at least how I feel about it and how I have experienced it since ~20 years of internet. x)
So don't worry; what you are experiencing is quite common I would think. ^^
The best thing you can do is this: Bring your own little bit of variation. Post things you enjoy, welcome new users when you spot them and offer them a helping hand - and if you do see some kind of toxicity in the replies, make sure to showcase the users that not everybody on the platform is a butt. First impressions matter so much. :)