Most of the start-ups are like this. Try joining a well funded company which has a good foundation or is a subsidiary to a bigger firm. Issue here is money, and the indian scene. Overworking employees in our country is the norm. All the local startups in my city are very Very toxic as well. 12 hour work day , shit pay during training period (4 months, less than 10k ), and one of my friends was in this startup and didn't like all this crap so he just gave up mid training because it was pure harassment at that point, so they called his parents to complain! They know that suburban/ rural kids are scared of their parents/ have pressure of some sorts from them. Extremely toxic.
I'd say stop looking at the startup area, because they have a lot of work to do. And they are obsessed with getting work done with least expenses.