I think Giroud was a problem, but I don't think he is to the same extent anymore. Giroud of today, is capable of winning the golden boot, his shooting metrics suggest that is not at all unreasonable. Its not quite as likely as Aguero or Kane, but that is not a purely Giroud issue. Aguero is a top tier striker putting away chances to a better degree than you would expect with consistency, but other than him, someone like Kane is mainly just getting more shots and shots from which you would expect more goals.
I think if Arsenal are looking at winning the league considering all the factors (the market for, the clubs prowess in the market, the attractiveness of the club, ability to drop $, and the big one of the direction of the PL at present) as a team you'd be better off looking at building a league winning team to feed Giroud than you would be looking for an Aguero who will allow you to win the league without deserving it, pretty much. Getting a more clinical striker than Giroud is just a waste of time tbh, margins are so fine and also so unpredictable season to season that considering the market you'd be dropping crazy money on anyone proven, to get best case a little bit better. Lacazette for example, you'd be looking at 17 goals to Girouds 15 off the same chances, considerations aside.
When you look at predictors of good teams, of chances created and goals scored. I would look at two things, one being the speed of Arsenal's play which is sluggish (genuinely only slightly better than LVG) and your increasing reliance upon Ozil the last couple of seasons (if he's out long term, I would think you are genuinely ****ed). In that sense you'd be better off improving elsewhere. The only time I would think Arsenal should be 100% looking to ditch Giroud would be if you could get a player who could either carve out chances for themselves to a significant degree or flash them away like Aguero. However if one of them stands out, you'll probably face some serious competition and again questionable how repeatable/predicable this is.
I'd be looking at your midfield set up, no more Ramsey Flamini combinations, and your right wing considering Walcott is out of form and ill suited to your current style. Perhaps having another look at someone like Draxler and letting Alexis work off the right, or Lacazette playing as a wide forward. All this is assuming Wenger can get the team playing to a league winning standard which is something I doubt more than ever.