Swiss railways are set up to run punctually and give through connections at many stations so if a connecting journey is advertised (check Swiss operator SBB’s planner) then yes, it is possible and expected that people will be making this connection.

It is certainly the case that with short connections you really need to be paying attention and ready to leave as soon as the train stops, if you are unsure and unfamiliar with the station I would suggest asking the train staff about the connection, they will be able to help you.

You didn't mention wich trains are involved in Lugano, or what your complete journey is on that day. Most probably it's a connection between Switzerland and Italy, but in that case, the direction is important. If your first train comes from Italy, I wouldn't risk it, unless there's a backup train from Lugano. There often are in Switzerland, but you didn’t mention your final destination that day.

And there is not that much risk if you miss it or are too slow: in Swiss nearly all normal trainlines run at least hourly and often ev 30 mins.

Such short transit are quite often ´same platform - other side´=just walk over. or not.

That is not the case in Lugano.