They do a fraction of the data manipulation options available from pipes and they require connectors being custom developed, plus they limit you on result delivery, which cannot be pulled.
* Formatter -- https://zapier.com/help/formatter/
* Filters -- https://zapier.com/help/filter/
* Webhooks -- https://zapier.com/help/webhooks/
* Code (JS/Py) -- https://zapier.com/help/code/ or https://zapier.com/help/code-python/
Plus if you want -- those custom developed apps can be added by anyone, for free: https://zapier.com/developer/.
The real value of pipes was to pull data out from any compatible client. Wonderful for processing data and have it pulled from a feed reader, not so as a trigger engine, for that zapier abd ifttt are better, but to straight out pulling data from a reader processing websites on demand, none of those could replace pipes.