When you read old threads, you will hear of many soft forks and including a few hard forks that gave birth to Bitcoin Cash , Bitcoin gold, Bitcoin SV. The last one should be BSV in 2018.
What happened differently that there are no threats or signs of forking?
I think block size war is a contributing factor. If we account for all the contentious hard forks between 2015 and 2018, we will can trace vast majority to disagreement, particularly the case of block size limit.
To answer the question "What happened differently" I will simply say the Bitcoin ecosystem matured. The main tensions that caused forks have cooled off, and Bitcoin’s development has shifted toward incremental, backward-compatible upgrades, reducing the threat of contentious splits.