I liked it much more than I thought I would, mainly because of the reasons stated by OP. It also pulled "weakest, but OP" card really nice - protagonists basic "firepower" is low, and doesn't change much throughout the series, most of his powerups are external and/or limited in use due to terrain/usage/time/etc. limits, so he has to be creative with his methods, and most of them are hinted on/explained/foreshadowed beforehand, so it doesn't look like asspull.
Series even features male support characters that aren't comic relief who are OP in their own ways and cover for MC's shortcomings and even get laid before MC
Overall it's rather lighthearted read, though it does periodically hits in the feels darker moments, especially when it comes to religion and politics, and not in typical "bad nobles bad" way - most of the time their actions have pretty solid reasons behind them, even if consequences are really unpleasant.