The Apostle Paul addressed his Epistle to the Colossians thusly: To the saints and faithful brethren in Christ who are in Colosse, etc.
Also, Paul wrote “to all the saints in Christ Jesus who are in Phillipi, etc.; and, on another occasion, “To the saints who are in Ephesus, and faithful in Christ Jesus.
No account is given as to how those folks achieved sainthood.
Many of the bible connotations were in greetings. Notice that it is saint with a small ‘s’.
Catholic Saints go through a decision process to be called first, venerable (holy person), blessed (beatified/beatification, and last sainthood with a CAP ‘S’ and they are then addressed at Saint.... or Saint.
So in a way we are talking about the same thing — living good lives on earth, but also different things because of the Catholic process.
Rather it is better to wait for the title of saint to come out until one passes on.
And --- as you note ---Saints have been honored in the Church since the first century of the Christian era. But the complex courtroom-type process to evaluate a candidate for canonization wasn't set up until 1,000 yeas later. And this was, in part, to stave off the "popular vote" honors going to war heroes, matriarchs of nobility, rich donors, sweet pretty girls who died young, and others who may have appealed to people on a celebrity level, but who might have had a certain mediocrity as to faith and morals.
Therefore the bishops installed a process that would take years, hopefully after the first emotions about a local celebrity's death had died down (typically a generation later) and there was still time to interview people who knew them, examine their writings in detail, see if the Devil's Advocate digs up any dirt, pray and wait... and wait ... and wait... for a couple of authenticating miracles, etc.
I personally favor this method, and my own opinion is that Pope Francis acted WAY too fast to canonize these two popes, especially +JP2 (although he does two well-attested miracles linked to his intercesssory prayer.) In my opinion, they should have waited until 2050 r so. But---
That'll be two cent, please.
There's my two cents' worth.