To borrow from the TV Tropes (https://tvtropes.org/pmwiki/remarks.php?trope=Main.CondemnedByHistory) site:
At-the-time, they (https://tvtropes.org/pmwiki/pmwiki.php/Series/Arrowverse) were praised for kick-starting a renewed superhero TV boom in a similar way the MCU had revitalized the superhero film genre, and for providing a Gateway Series (https://tvtropes.org/pmwiki/pmwiki.php/Main/GatewaySeries) for new fans of the DCU; nowadays though the entire franchise is looked badly upon, early seasons included, for the melodrama, Romantic Plot Tumor (https://tvtropes.org/pmwiki/pmwiki.php/Main/RomanticPlotTumor), Adaptation Decay (https://tvtropes.org/pmwiki/pmwiki.php/Main/AdaptationDecay), and a variety of issues with their writing, never mind that the early seasons were primarily directed by a showrunner who was outed as a sexual predator. There's still the occasional 'the first season was good though', but even that is becoming rarer, since people who look back on them now tend to notice the Franchise Original Sin (https://tvtropes.org/pmwiki/pmwiki.php/Main/FranchiseOriginalSin) nature of the later issues.