I suppose that everything depends on the type of work people have, as, we’re still unfortunately, we’re still spending the majority of our time on theat work.

The comma should go before "as" here :)

Either "we're still unfortunately spending the majority of our time at work" or "we're still unfortunately spending the majority of our time with our work" sounds good - saying "on the work" sounds strange.

It’s inevitable to use messengers every now and then if you’re coordinating some processes, for instance.

Furthermore, those who frequently use messengers (or social media, or even PCs) at work usually get so tired of ithem that they try to skipavoid using gadgets in their spare time.

You have to write "them" instead of "it" because "messengers" is plural.

Ok, ithis might be a bit exaggerated, but I'm pretty sure they reducetry to reduce the amount of time spent texting and hate answering phone calls.

I suppose that adolescents have never lived in a sans-messenger world, that’which is why they’re much more accustomed to using them, while adults get really tired of constant pressure and need to answer and. Therefore, it’s much easier for them psychologically for them to limit messenger using.

What you wrote was a run-off sentence, so I split the sentence into two.