Is it a Sin, to be Late at Mass?

As far as the issue of punctuality at Mass is concerned. It’s good that we as Catholics get to Mass early not late, because it is during the introductory rites that we begin to adore God in communion with the brethren and to prepare the heart for the Eucharistic celebration with the community.
I vividly remember being told as a child that if you didn’t get to the church before the proclamation of the gospel, the Mass didn’t count. Obviously, then, lateness had consequences. Anyone who goes to church late commits a mortal sin and had to go to confession or, if available, had to stay for the next scheduled Mass.
Whereas before the Second Vatican Council some moral theology manuals placed coming to church before the gospel or the offertory as the “dividing line” in deciding if one fulfilled their Sunday obligation, most priests and liturgists are so reluctant to give a defined answer to the question: “How late is too late?”
There are also those who talk of lateness to Mass as an “abuse of communion”. Which means that if you are late to church, don’t receive communion. A story was told of a woman who would habitually come for daily Mass at communion time. When she asked why comes to church late, she reported that she does the readings at home and didn’t feel the need to hear what the priest had to say and that she only needed the Eucharist. In other Words, we need to remind ourselves that the liturgy of the Word is not a prerequisite for receiving communion. Lately people have talked of lateness to Mass as a “vice” and have blamed this increasing tendency on technology and the Millennial generation.
But in everything, try as much as possible to be early to mass so as to prepare yourself for the Eucharistic celebration. In fact, St. Alphonsus de Ligouri once wrote that if we had 100 years to properly prepare ourselves for our first communion, it would not be enough for us. Coming to Mass early puts us in the right state of mind for what we are about to enter into.
In some Churches, the priests would always wait for people to show up before he starts the Eucharist celebration? Some Priests most times delay the Mass until the church is filled up. Most of them starts a 10 o’clock Mass at 10:15. And this doesn’t solve the problem, instead the late coming becomes worst and people start arriving at 10:25. In this case, It’s advisable for the priest to start the mass at the scheduled time. Whoever will be late will still be late.
If you have the habit of criticizing or judging people that comes to church. Be reminded that it’s not a crime nor a sin when people show up late at mass. Be it 5, 10, or even 20 minutes late, what matters is that they are there to give thanks and praise to God, to be strengthened by the Eucharist, to say pray with a community that shares their faith, and to pass on that faith to their children and grandchildren. And in all, they choose to be at Mass rather than hitting the snooze button and turning over or meeting friends for brunch. If we in any way judge and criticize them we run the real risk of losing them.
So even if you are a like me that judges those coming late to church, let’s hold our judgment and our tongue and welcome all to our liturgies, even if they miss the gospel.
See Catholic.org article written in 2018 has the exact same referenced and words. You may want to give credit due to the source of information.