Hey there. I'm somewhat of a a fan of all in one ETFs however I think many of them have the same issue, that being too much exposure to the Canadian markets.
Keep in mind, I don't mean holding too many Canadian stocks. There are plenty of solid Canadian stocks that are not over-exposed to the Canadian economy and even though they're Canadian corporations, they operate globally or at least in North America. Think of a company like Park Lawn Corporation, Couche-Tard, BRP Inc, Constellation Software etc.
However, there are also plenty of cyclical holdings that are over-exposed to the Canadian economy. Most of these funds hold composite TSX Etfs, meaning they have hundreds of Canadian holdings. I personally like to isolate my Canadian holdings down to a select few so I can avoid a lot of the companies I simply don't want exposure to.
Many of the all-in-one funds have anywhere from 35-40% Canadian exposure despite the Canadian economy making up a very small portion of global GDP.
For the lazy investor, as you mentioned, they certainly work.