Uber is still illegal and in general does not operate in Ubud, many of the local communities (banjar) have banned them as well. It's a convoluted government system, but some roads are national, or provincial or local roads depending on certain factors. Eg in some villages, they actually do not want even regular Balinese drivers from outside the villages to pick up. Some villages impose an entry fee with an eye to this. For example, I've had to pay to enter Nyuh Kuning if I drive in with a driver not from that area.
Also Uber drivers are often not from the area they are picking up from, because the app, which is based outside of the country, doesn't differentiate between drivers who are Balinese from that particular area or drivers from other islands who have just migrated to Bali and are using the app to help them get work. In some cases, the local Balinese have had their suspicions because the driver appears to not know the area, is not Balinese, and seems to be waiting for their fare at streetside rather than picking them up at a hotel or restaurant. These are often when the conflicts have started. Of course this is just a slice of what is happening and there are plenty of different scenarios but just the ones I know about.