I've several married friends (all Hong Kong locals) chose to have pets over kids, and that's also my preference - except I don't want to have pets either.
By the way, there are 150 mainland Chinese migrating to Hong Kong, daily [2]. That means "original" Hong Kongers will be rare eventually.
[1]: https://blogs.wsj.com/chinarealtime/2014/09/04/want-to-raise...
[2]: https://www.hongkongfp.com/2018/08/15/41000-one-way-permit-h...