Inter could be stronger and more successful without Simone Inzaghi if the new coach is truly able to make his team better. Player performance of course influences the final results of a season, but the coach's ability and strategy also have a big impact. Napoli, Inter, Atalanta and Milan will still fight for the title like in previous seasons and one of them will win it.
Inter Milan just lost Simone Inzaghi to Al Hilal and they will face with a chaotic season with a new coach. Inzaghi seems to find disagreement with Inter Milan on how they can spend money for squad improvement and together with very good offer from Al Hilal, he decided to leave Inter Milan, Serie A, Europe for a 3 year adventure in Al Hilal and Saudi Professional League. It will help his finance a lot within only 3 years, and after that he will be able to return to Europe, so this adventure is worth to try with Inzaghi.
I don't choose Juventus as a title contender next season even though they can still be expected. Juventus' performance has completely changed in the last few seasons and therefore they no longer have a better chance in the title race. I think Napoli will still lead the favorites list, Inter is close behind.
If Conte joins Juventus, he can help them becoming a true title contender because Juventus have better players than Napoli. In addition, Napoli might become weaker without Conte, and the same with Inter Milan. A next season, Atalanta might become weaker too by losing Gasperini so Juventus can take advantage of big changes at coach positions in their competitive clubs for winning a first Scudetto after many seasons.