When you're done virtue signalling with your flaccid steel, you could try just reading the series instead of making nonsense comparisons that have no relevance to...anything
I feel you're screaming into the wind there, friend. Those that stopped at chapter 3 either projected their own fears and insecurities or have a lack of a functioning brain. In either cases they should not roam the internet unsupervised.
For anyone that cares, I'll spell out what chap 3 was about and its use story wise and moving forward:
-The setting is a SOL romance between a socially akward people pleaser that is overly self concious and an outgoing free spirit that goes at her own pace and is otherwise unfazed by the judgement of others.
They have this classic appeal of personalities that compliment each other.
-We follow the POV of the introverted kid, as is often the case: more useful for narative purpose, since he ponders deeper in his thoughts, and being self concious his feelings are clearly conveyed to the reader.
-The first few chapters are used to introduce the setting and characters and their relationships, for example, the main "couple" are not childhood friends, they just got to know each other so we see the relationship devellop from point zero: strangers. Since we as the readers discover things at the same time as the main boy, other characters are needed to establish a mainline of how they interact with the world and do some basic worlbuilding/setting to flesh out the story and characters (family, friends, main personality traits, etc...)
-that's where chap 3 comes in: it establish the mainline of how Tsumiki interact with the world and people in general, not just our main POV guy: it shows how actions that would seem intimate to the MC (which at this point already caught feelings) are nothing special for her. The point is, roughtly, that she's nice to everyone, so don't misunderstand. And from there we're going to see the evolution of "I like everyone", to "MC is special amongst everyone". (very heavily summarised plotline).
So don't freak out, it's basic romance storytelling. Also, in most recent chapters FMC is getting some competition for MC's affection. While he is mostly oblivious, the purpose is to awaken possessive feelings in her, aka jealousy.
For the most part I feel that our boy lack any real competition, even. I don't know if he'll ever get some, too, since from the writing pattern it looks to me like it's going for a "Komi san" approach with a mostly fleshed out essemble cast, instead of zeroing in to the main couple (where rivals are more important to further the plot).
In future devellopements I'd like to see some drawbacks to Tsumiki's traits. For now she's portrayed as the outgoing one that stimulates the MC to come out of his shell, being the metaphorical shining beacon to light the way. But if he only receive and have nothing to contribute to her devellopement then the story'll be worse for it, and it would be a shame.
This concludes my ted talk for people who lack reading comprehension (and other interested parties). Thanks for listening.