It's better than the alternative, but still far from perfect. Unemployment benefit is supposed to provide you a safe net should your employment lapsed - so no one really expects that you would maintain the same quality of living. If push comes to shove you can and will cut all the excess (entertainment, dinning out, traveling), leaving with just bare necessities.
Now, with the parental leave, when your expenses rise (diapers, formulas, cloths, ...) you're expected to make do on the same barebone salary replacement. I've experienced this myself quite recently: I had a choice to take parental leave and get a huge pay cut, or just burn through all accumulated vacation time and get back to work early.
Currently, Service Canada web site says that "maximum yearly insurable earnings amount is $53,100" - which cuts your income 3-4 fold you choose to stay at home. I think many high-earners (read: more that 53k) would rather choose to have more deductions throughout the year, but have 70-80-100% matched.