Personally don't love that. It is going to take a few years to overhaul the squad. If he can't get more out of it now he might not have it.
I think your concerns aren't as unreasonable as some are making out here mate.
While I do fall on the side of, particularly post-Burnley away, he set us up exactly how we needed to be. Hard to beat, complete work-rate off the ball, get in front and see games out... I do agree he made mistakes, especially early on when we just got obliterated when trying to play football.
However, 3 things to consider:
1. A good manager changes it when something clearly isn't working. Not addressing this was what kiled off Martinez, Koeman, Silva and Benitez to an extent. Lampard did change, I think for some he left it a bit late which is fair, I personally think like many managers before him he's came in and seen a team full of internationals and thought maybe they just need to be allowed to play footy and everything will be sound. Thankfully unlike some of his predecessors, he changed it up and got the results we needed.
2. When Lampard first came in, he wanted us to get the ball down, play and control games. I think everyone would agree with you that we should be aiming for that. I think it stands to reason that with a full pre-season with the squad, we will see at least some return to the team being more set up to play with the ball rather than without it. I would like to think that the demand for maximum effort, fight and grit Lampard instilled in the team in the end of season run-in will be our baseline off the ball at least while we try to improve what we do with the ball.
3. We shouldn't be completely dependent on getting all the manager's ideal transfers in before we can assess the job they are doing. A good manager will get more out of players who have not really kicked on under previous managers. I personally, am encouraged by seeing this in Iwobi. Richarlison and Pickford aside, Iwobi was the player of the season for me since Lampard came in and by far the most improved. We will not get all the players we need this summer, so it's essential we see more of this developing the players we currently have if we're to progress. In short, I think there are some positive signs that Lampard will be able to offer us that ability.
I think people have to remember that Lampard is very, very early into his managerial career. He has only managed 2 full seasons in his 4 years of management. He got that Chelsea job way too early and was always destined for the sack given what Chelsea had always been in the Abramovic years. Mistakes will be made, but for me I see a guy who actually learns from his mistakes.