People tried creating alternatives for MS Office, over the decades. Didn't succeed. Not because of technical moat. Some companies like Google reworked internet serach problem. They succeeded because of technical moat (page-ranking) and later they quickly moved on to the more common moat - user base, supply chain hijacking (ads) and branding. Social media firms hardly have any technical moat. They 100% rely on locking of user base.

Technical work let's you enter the field, but the survival depends on the squatting in the supply chain routes or locking away your customers in your dungeons.

Social media's moat is network effect