The article you cited didn’t substantiate its claims. Someone else posted evidence that in fact attendance was mandatory from the early Church on. The article is right, however, that Mass attendance looked very different from the way it does today and would have involved a lot of “milling around,” not people sitting in pews quietly.
And the Eucharist wasn’t given weekly but sometimes annually.
The Eucharist was celebrated daily. Most of the time, only the priest received communion. Laypeople had to receive annually, and might receive several times a year if they were devout.
The distinction between celebration and reception is hard for Protestants, and Catholics get confused too because they receive quite frequently nowadays. People also get confused about Protestantism, thinking erroneously that Protestants began celebrating the Eucharist less frequently because they didn’t think it was very important. On the contrary, they insisted that whenever it was celebrated at least some in the congregation should receive. So pastors would only celebrate when they knew there were people ready to receive, which wasn’t very often–usually quarterly, which was a bit more often than most laypeople had been receiving.