They are playing catch up with Anthropic's in this functionality. Claude's app was unified and extended with new use-cases since pretty much the very beginning and OpenAIs approach is just a reflection of their attempt too shoot for all targets once (with independent teams, of course).

Don’t think this article should frame consolidation as a failure of the individual bets.

The reality is likely that shipping these separately was (1) faster given org structure at the time and (2) made sense in the environment (e.g. if Perplexity launches a browser and that turns out to be what users want, we should have one too). Better to iterate and move on then try crystal balling perfect projects.