It seems that people running restaurants realize that losing, or giving up, a Rabbanut teuda due to Corona problems (ie hechsher/teuda too expensive in the days of Corona) can be very profitable, at least in the short term. It becomes splashy news, and the masses come out to support the restaurant against the oppressive and insensitive Rabbanut. It might not work as a long term boost to business, but at least int eh short term it can give the restaurant a nice jolt.

A restaurant in Kiryat Ono, Hamaadaniya Shel Erez, put out an announcement that it has decided to give up its connection with the Rabbanut due to financial difficulties due to CoronaVirus, and that from now the public should know that it is operating without a teudat kashrut.

The only problem is that shortly after the announcement one of the rabbis from the kashrut division of the local Rabbanut, along with the Chief Rabbi Rav Ratzon Arussi, responded exposing the announcement as fraudulent as this restaurant has never had a teuda from the Rabbanut, so it isn't giving up anything. They have operated until now without a teudat kashrut and are continuing to do so.

To explain further the rabbis said that the restaurant owners did recently request a teudat kashrut. They responded positively to some of the Rabbanut's requests, but they refused other aspects of the Rabbanut's concerns, such as food sold on Fridays being supervised.

The Rabbanut stressed that this restaurant never had a teuda, and had only started communicating with the Rabbanut about the possibility but it had not ended with any certification. They were granted a temporary authorization, without a teuda, for 2 days, based on a promise about kashrut on products sold out of the city. Immediately after that they announced that they are giving up on the Rabbanut and will be operating from now without a teuda.

The restaurant owners responded saying that they really planned on getting a teuda from the Rabbanut since the restaurant is really kosher anyway, just without a teuda, but when they saw the massive investment they would need to make based on the requirements of the Rabbanut, they decided they could not do it. They said there was a mashgiach from the Rabbanut each day with a temporary kashrut teuda and this was coordinated via the Rabbanut. Because they had announced they were kosher with the Rabbanut (ie on a temporary basis with intent to become permanent), when the communication with the Rabbanut was ended, integrity demanded of them that they announce that they will no longer have the Rabbanut teuda.
source: Kikar

As King Solomon said, only God knows what is in the hearts of man. We don't really know if this was a scam or an honest attempt that just didn't work out. but it looks really bad (from the little we know). Sure, the Rabbanut has a lot to work on and we all know how difficult the Rabbanut can be - that does not mean every claim against the Rabbanut is fair and justified and even true. This is nothing like any of the other recent cases. if a non-kosher restaurant, even if they claim they were technically kosher before, wants to become kosher, they are going to have to make changes and meet the requirements, and that takes investment.