Who each tool is really for
Bitrix24
Bitrix24 is generally chosen by companies that want one place for internal work and customer work. Tasks, internal communication, documents and CRM records sit together, which suits organisations without an established intranet or project tool and teams that value seeing everything in a single workspace.
Zoho
Zoho is generally chosen by companies whose priority is the sales system itself. The CRM is the centre, and the wider catalogue is there when other functions need software. It suits businesses that already have collaboration tools they like and do not wish to replace them to obtain a pipeline.