I wouldn't say the carrots failed entirely to entice them. The fact is that there are a lot of positive results that are not captured by mainstream media, probably purposefully. Sure, many of them probably don't want to live under CCP model of governance, but a lot of them have been attracted by China development and China new found softpower like Cdrama or Cpop. A lot of intermarriage between Mainlanders and Taiwanese too. DPP tried to block this, but they found their way to Taiwan nonetheless. Taiwanese also continue to go to Mainland to work and do businesses. These are valuebale ties that will disappear if China cut them off completely. It will be a win for the separatist if that happen. China need to expand the ties even if DPP try to block it.

Taking the eggs example you gave, I think it was the Taiwanese that lose out in that case, and their lost will transform into resentment towards DPP as we can see in the latest election where DPP couldn't win convincingly. Clearly a lot of Taiwanese are tired of DPP sabotaging the economic ties with China, harming average Taiwanese in the process. If China cut off the ties completely, then DPP win. DPP will argue that it was CCP that cut ties, not them. Taiwan is running trade surplus with China because it is exporting a lot of spareparts to China to assembly and then export it to global market. It is their main export, and China is their center of assemblying. I wouldn't be too confident that they can't find replacement, maybe not in the short term, but in the long term? If Vietnam can't replace China, what about Vietnam + India? If they still can't replace China, add Mexico, add Indonesia, add Bangladesh, etc.

Will the carrots bring reunification? Right now, CCP is betting that continous engagement with Taiwanese will bring some emotional bonds between Mainlanders and Taiwanese. Will that translate into peaceful reunification? Nobody know. But even if China has to invade Taiwan one day, hopefully those emotional bonds will make it easier to pacify the population. I think it is easier to subdue people who have ties with you, including family ties, than trying to subdue complete strangers.

Btw, if China really want to cut off Taiwan, to make it work, China has to blockade them totally, to make them isolated politically and economically. In few years, their economy will be in shambles, and their standard of living will fall into poor countries category. Poor people will probably be more open to reunification if that means they can come out from poverty. But as long as they have access to global market, they will still have lifeline.