One of the comments already posted is correct…not everyone in the Jewish community of that era is going to have as strict an observance as you may be envisioning. This is why the preaching of Jesus was so powerful to the ordinary people who could better understand Him than they could the scribes and the pharisees. Matthew, when he was collecting taxes and before he was called by Jesus, or the woman caught in the act of adultery, for example, among others, well indicate that not everyone was perfectly observant of the law by any means.
Most of what we perceive as their strictness was part of the ordinary flow of their lives. Imagine if they saw us today: women getting up and putting all this stuff on their faces, blow-drying their hair, taking a bunch of vitamins… and all that just to get out the door! They would probably think our lives terrifically complicated!
The Pharisees were strict, bit not all Jews were Phaisees.
I think it’s more accurate to say that just about everyone had their own interpretation of how to observe the Law. Some of course had a laxer interpretation than others, but most Jews took the Torah seriously: it was a part of their life, their culture.
The Pharisees were not really as strict and legalistic as we often imagine them to be. They were ‘strict’, not so much in the sense of ‘most extreme’ (some groups, like the Community at Qumran - who may or may not have been Essenes or a similar sect - had more extreme interpretations of the Mosaic Law), but that the people thought that they had the ‘most accurate’ interpretation of the Law.
In a way the Pharisees are actually more lax about certain things than others: where some people would advocate a hard-line literal interpretation, the Pharisees will sometimes find a way to observe the spirit of the Law but without necessarily following it literally. For example, Jews thought that they were not allowed to carry burdens out of their houses on a Sabbath (Jeremiah 17:19-27). Some people will take this to mean that they’re not allowed to leave their houses.
But the problem is, the Sabbath was often the only day in the week when people would be free to meet with each other and do things like festive dining (each family brought their own dish). What did the Pharisees do? They decided that when several houses were next to each other along an alley or around a court, these houses could be connected with one another using a symbolic enclosure, say a series of doorposts and lintels, thus making all of them into a single ‘house’ (
'eruvim). That way, neighbors could carry pots and dishes from one part of the ‘house’ to another and thus meet and eat together on a Sabbath.
Some people will of course find the Pharisaic solution a bit of a stretch (even with an
'eruv, people are still carrying stuff out of what people would call a house!), but that’s the thing about them: while at times they do advocate a strict interpretation, other times they made the Law less restrictive than a literal interpretation would have it. (For the most part, the Pharisees made special rules only for themselves; they didn’t force them on everyone else. Maybe many of ‘the Pharisees’ Jesus met were the noisy radical types?

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In a way, it’s tied in to the Pharisaic concept of the priesthood of the people: they taught that laymen can and should also follow the Law and the statutes in it, not just the priests in the temple - because all the Jews are, according to Scripture, a ‘kingdom of priests’. (Pharisaism was a largely laity-run movement and many Pharisees themselves were laymen.) Hence they took steps to make the Law more accessible to the average joe. And the people respected them in return, to the point Josephus claimed the Temple priests - who traditionally were
the interpreters of the Torah - usually followed the Pharisaic interpretation as a concession to the people. (Many of the chief priests, who were aristocratic, were likely Sadducees; there were some priests who were Pharisees, but for the most part, Temple priests, like most Jews, did not belong to either party.)