Are Arsenal currently a mid table team?

Yes. Arsenal have a weak squad in comparison to other teams in the top half of the Prem, whether it's down to personnel(compared to the top 5,) or the squad chemistry/cohesion(compared to teams from 6th-10)

I'll start with the teams signings since 2018. Aubameyang, Mkhitaryan, Leno, Torreira, Ceballos & Sokratis, all objectively good footballers, but not good enough for a team that is meant to be pushing for top 4, or even going 1 step further. They're not suited to the club.

Leno & Aubameyang, Arsenal's most important players as of late, also outline the problems at the club. They're doing the business throughout the season, apart from the times when the club needs them the most. Leno & Aubameyang were not good enough after matchday 30 of 2019/20

They also weren't good enough when it came to the UEL, especially against Olympiacos this year.
They're good players, Aubameyang isn't a striker that will lead you to glory, no matter how you view it.
Leno, Incredible shot stopper, but so so painfully average everywhere else

You can say that they both are the reasons that Arsenal aren't in the relegation zone, but honestly, who cares. I've watched Szczesny & Giroud lead this club to top 4 finishes consistently, Leno & Aubameyang in comparison, are good, but clearly not good enough to do that.

Torreira, a player that has not been good enough for Arsenal after that 5 game spell in 2018. Why? He isn't suited to the prem, same goes for Sokratis, and for Mkhitaryan, who's doing well in Italy.

They all need to be sold this summer, so Arsenal can properly rebuild

Another reason why Arsenal are in this "bad situation" is due to Raul Sanllehi. Edu Gaspar had his doubts about Unai Emery from early on, and It was due to Raul Sanllehi (who shares the same agent as Unai Emery) that Unai Emery was sacked weeks after the international break.

Recruitment during Summer 2019 was not as good as we needed it to be. They started the window by targeting Dayot Upamecano, and ending up with David Luiz on deadline day, which sums it all up. High hopes, but ending up by taking anything on the table.

Let's also look at the 2 homegrown defenders that are coming back from Injury. Rob Holding & Bellerin.

They've been defensive liabilities, Bellerin doesn't look like how he used to be & Rob Holding has helped us concede 7 goals in his last 2 matches. They need replacements.

On that topic, David Luiz we need to keep him on reduced wages for another 12 months MAX, if we want to integrate Saliba into the team properly.

We have more sellable defensive assets we want to sell. Sell them, and keep David Luiz as a backup for next year.

Matteo Guendouzi, Bukayo Saka, Gabriel Martinelli. No matter how you view it, They are the shining lights of this season.

Arsenal need to build around them, Martinelli LF/CF, Saka LCM, and Guendouzi DM/RCM.

We may have a mid table team, but it's a team with a strong youth core.

The youth core need to be supported, by expecting them to play with players that either aren't good enough for Arsenal, or players that aren't consistent when the team needs them the most, they're being told to gel into a team where they'll be the best performers.

Nico Pepe & Kieran Tierney are another 2 players that are capable of playing for Arsenal week in week out for the next 5-10 years, even if Arsenal turn into a top level team.

The rebuild job has to be based around the youth core, with William Saliba, Nico Pepe & Kieran Tierney,

Not commenting on Alex Lacazette because of how well documented my thoughts on him are.