To give an idea of what is happening, I'll try to explain what I know, which isn't lot.
Since last year, there's been an increase in fees that every transaction has to pay to get confirmation within a reasonable timeframe (the point at which your transaction is deemed a valid one). The reason for this is that, the Blocksize is capped at 1MB. Now, the problem is that people are disagreeing with the direct solution to this problem, which is increase the blocksize.
What that means is that only 1MB worth of transactions (I don't exactly know how many that is) will fit in a particular block, which is generated once every 10 minutes (the difficulty of 'mining' is actually adjusted to ensure this). So since there's been a lot of activity with bitcoin, a lot of people are having to wait longer to get their transactions confirmed because they usually have to wait for the second or third block after the transaction is sent out by the client. This makes confirmations slower.[1]
Now, to make confirmations faster, people have to pay more for the 'transaction fee' which directly goes into the pockets of the miner who includes the transaction in their block. So transactions which pay lower fees are pushed out of the block the miner is currently mining because, they obviously want more money. So the transaction usually occurs in the next block, if they're lucky.
The way I see it, the blocksize has to be increased, because it is ridiculous that I have to pay more in fees for sending bitcoin than using paypal. But, the party opposing it has some interesting arguments too. (The full pro-con list can be found here[2])
The strongest argument in my opinion is that making the blocksize larger would lower the transaction fees the client has to pay. Now, that is good for the client, because they pay less fees. But, bad for the miner because they get less money for all the work that they put in.
So there was talk about increasing the blocksize to 2MB. That never went through, because of some other problems with SegWit, which frankly I have not much knowledge of.
But then came the idea of Bitcoin Unlimited. Now the people behind this say that the blocksize should be WHATEVER the miner chooses and they want autonomy over the blocksize. What can happen in this scenario is that the big players can make a loss temporarily while the smaller players lose money. Eventually the smaller players (miners) close shop which would make bitcoin more centralized.
Very interesting arguments on both sides, and this will be much more interesting to watch than anything in recent history.
I'm actually surprised not many people are talking about this, and that there's more interest in whether Bitcoin is accepted as an ETF, which was a terrible idea in the first place.