Why buy Dot (Polkadot)?
1) Polkadot solves the problem of interoperability in blockchain, where most networks currently function as separate islands of data with little way of utilizing the information the other networks possess.
2) When you buy DOT, you gain the ability to vote on upgrades to the Polkadot network, with each vote being proportional to the amount of DOT you choose to stake. Alternatively, you can also delegate your tokens to stakers, allocating votes to other users in order to earn a percentage of new DOTs minted by the protocol.
About Polkadot Network
1) Blockchains that exist in isolation can only process a limited amount of traffic. Polkadot creates a sharded multichain network, meaning it can process many transactions on several chains in parallel, eliminating any bottlenecks in processing.
2) Networks and applications on Polkadot can share information and functionality like apps on a smartphone, without needing to rely on centralized service providers.