I guess you could say that but generally there has been filler content in all the seasons imo, you also get flash backs at times that are meaningless and add very little to the show. They were trying to develop canary which was good but again it lacked the depth of a top tier show now that isn't bad thing given Arrows identity as a TV series. Also you have all these mini B or C plots brewing when the main storyline takes a bit of a break, you could say the B/C plots are interconnected to the main feud involving Olly and Rahs Ul ghul in the grand scheme of things if you look at it a bit deep but again they lack depth.
With the whole Laurel thing, they never really had to build her so much it was all about her wearing the suit. Her character change came when her sister died and since then she went from that girl who is always bitter and moaning about stuff to wanting to get out there and fight, they maintained that theme after the mid season.
I don't remember what happened now lol have any episodes released after the one where Olly went to rescue Malcolm ? haven't watched it in a while, I think they are gone on another break?

Yeah the stuff after the mid-season tends to be the best.
The most recent season has not been that good in comparison to the stuff they did before but I guess they had to because Mike had been working with Harvey for so long, but it's a similar show to Arrow in the band of a Mid-Tier when you look at them overall. Neither belong in the Top tier with the likes of GOT, Breaking Bad and Sherlock