The Blockchain Trilemma describes a number of common obstacles encountered during the technology's implementation.
The decentralization, security, and scalability that make up a blockchain are the common challenges that many organizations face with the technology because it is difficult for a blockchain to have all three distinct characteristics.
Some blockchains offer greater security and decentralization, but their scalability may be poor, causing the network to transact at a snail's pace.
Additionally, there have been instances in which a network has more scalability and decentralization but less security, creating a dilemma for the majority of networks in which many organizations are unable to decide which of these challenges is more convenient for them.
This was not a problem when bitcoin was first introduced because the bitcoin network operates smoothly with full decentralization, security, and limited scalability. However, when millions of users adopt this method, scalability becomes a problem because the networks weren't ready for much power at first.
However, as time has passed, scalability has been solved by adopting other methods to improve transactions that divide the workload among nodes, and this challenge has been drastically decreasing, bringing more positivity to the blockchain technology as well.