Now it makes sense to say that previous matches and consistent performance in the Domestic League cannot be completely used as a benchmark, because playing in the UCL is very different. Of course everyone was shocked by Arsenal defeat to Lens, and it is evident that surprises happen more often in the UCL. Even though on paper Arsenal has a better chance than Sevilla, that doesn't mean the opposite can't happen, but if you look at the statistics, Arsenal should be superior.
Even though I'm not really sure Arsenal can get 3 points this time at come to Sevilla, I don't think they will lose that match. Sevilla has an advantage because they act as hosts, then they have to create their own luck while hoping that Arsenal doesn't play well so they can take advantage of it, because whether they admit it or not, Arsenal is still better than Sevilla.
Was there a team in the last Champions League that weren't doing better in their own domestic league, clearly all the teams made it out the knockoit stage were among top 6 teams in their standing and guess who even won the Champions League, it was Manchester City and they went ahead to win treble after winning the FA cup. Domestic league performance matters but it can't be use as a benchmark in the group stage and also in the round of 16, this stages are sometimes luck due to late preparations by some teams or early preparations by teams people expected less performance.
There is no much data to and statistics for Sevilla and Arsenal but the emirate cup is enough to justify what they are going to play next. I'm not sure how prepare Saka injury is going to be but if we have Saka and Jesus starting that match like they did back then, they will quick finish Sevilla in the first half, been the host doesn't matter in this stage because Arsenal are better than them in all ramifications.