Friendly matches are not a worth to see games, they were played without fierce, and we see so many tries of players and tactics.
Some games are played with subs players and the one with starters are played without the real energy of a game, no one its gonna risk a injury. Thankfully its gonna end soon this part of the season called pre-season.
The pre seasons are good actually. It's a time for clubs to test their strengths. Know what they are good at and what they should improve on. It's a period to chose tactics that work best for the team and how to integrate the players together.
Also, it also create an opportunity for the team to bond, especially when you have new players. The players all fly out to a different country and they stay together for this period. That's a great opportunity for the team to bond and form some chemistry off the pitch which would affect the chemistry of their performance on the pitch.
The reason there is so many subs is because the coach is giving everyone in the team a chance to prove themselves. There are new players, academy players, first team players that are not starters, old players etc all fighting for a spot on the team, so they have to convince the coach that they're worthy to be trusted.
As much as the pre seasons are non competitive games, it's a good way to test how ready a team is.