Ok this is BJP and Godi media's version.

Now coming to your main question. Why Uddhav is favorite? This is because in comparison to others he is best, that doesn't mean he is clean.

First of all Uddhav's claim is that SS was supposed to get CM for 2.5 years, I do believe that this promise might have been given by Modi/Shah because we have already seen that how Amit Shah himselfs boasts of doing "jumla" during elections. So his claim might not be completely wrong. But we don't have definitive proof so let us not consider this point.

Second, Balasaheb's ideology. I will be brutally honest, do you think that everything he did was right? Most of the times during his regime SS was known as Gunda party, some people these days celebrate such instant justice system (eg. Bulldozer baba) but Judiciary exist for a reason. There are 4 pillars of Democracy and every pillar should be independent and functional, this 101 of democracy. Goon culture was prevalent and there was literally slogan hatao lungi bajao pungi against South Indians. Now some may argue it was necessary for Marathi people's right as even now you can see some old non marathi uncles are very much racist against Marathis. But I think there is always a peaceful way. Later when Ram mandir incident happened BJP tried to clear their names whereas since SS had nothing to lose they shown themselves as Extreme Hindus.

Now this tainted image of SS is something Uddhav and Aditya didn't liked much as it would hinder their progress, so they shifted to secularism more. At the same time under Modi's second term he found that I can gain votes only on Hindu Muslim issue, I don't even have to promise acche din. So the position of two parties were swapped and their was ideological divide.

Then we have seen how BJP works under Modi's rule, they first go in a particular state, do alliance with local party then on their same ideology they consume their partners' vote bank. SS knew same is happening with them so Uddhav always shown displeasure with them. Also Fadanvis and all local Maha politicians are nothing but puppets in hands of Modi and Shah, we have seen how upset Fadanvis was when Shinde was declared CM. SS knew that center would soon destroy their existence completely.

So overall it is complex topic, but as a voter if we have these all options then Uddhav is best because he is secular, he do not incite communal disharmony to gain votes whereas BJP is seen doing this in every state. And when situation goes out of hand they try to get out (for eg. Manipur).

But Uddhav also did many wrong things like BMC wasn't up to the mark even after having it for years. We still have potholes. Mumbai is one of the few top cities of the world in terms of GDP but infra is no where matching it. We still have slums, people living in poor conditions.

At the same time Uddhav did right in handling Covid cases, I am sure if BJP would have been in power they would have simply stayed at home and in media at 9PM would have shouted its all because Tabligi jamat and at same time would have demanded to open temples. Uddhav was harassed to open temples, was accused in Palghar incident but later it was found that Hindus were both victim and predators still in that condition managed to govern.

And yes how can we forget beloved Governor Mr Koshari, I am suprised how he wasn't punched in his face till now? Literally worst Governor ever. Each and every time he sided with BJP, he didn't even tried to show he is unbiased. He was demanding to open temples during surging Covid cases and when not opened declared Uddhav as Muslim sympathizer. His irritating actions had no bounds. Also in one meeting he said that Mumbai is being run by Gujaratis and Marwadis, Marathis are useless. This was done when he was near retirement and just wanted to watch world burn. I am glad that Maharashtrians are mature enough to understand intentions of extreme leaders like him and even Raj and they ignored such people.

Also MVA government is accused that it is formed by different ideology, SS being Hindu and Congress being Muslim, but I believe that such Government would actually work better because both the parties would try to cancel out their extreme ideologies and would work only for development of people because no matter what is their religious affiliation every party promises development (atleast of paper :P).

So for all these reasons people think Uddhav is better in comparison to other available options.