Barcelona's performance in the last 3 seasons is very weak. Barcelona's performance has deteriorated since Koeman became Barcelona's coach. Although Xavi has been able to stabilize the team, he has not yet been able to form a completely strong team. Barcelona need more experienced players in defense. At the same time now Barcelona needs experienced striker. If Lewandowski joins Barcelona, I think Barcelona will be stronger. Next season, the title fight between Barcelona and Real Madrid will intensify.
I agree with you. Barcelona had a terrible performance with poor results under the leadership of Koeman. The last time Barcelona won the La Liga title was in the 2018/2019 season. Xavi had a great impact on the team. However, as you stated, if they basically improve their squad with a good striker and also strengthen their defence. Barcelona will surely be capable of competing for the League title with their rival Madrid.