What about transaction fees? Will they increase as well after the halving as well?
There is no need for the price to rise for the miners to stay in business. The miners will just switch off 50% of the miners.
Today if you want to urge your transaction you can choose priority fees or if you have time to wait you can choose economy fees, there is a difference that is noticeable already.
If there will be 50% less mines, it only mean that blockchain is more vulnerable for an attack. Transactions will be still made. When number of transactions will increase that much to not fit in a block developers will increase the block size. there was lots of talks about that already, to make right timing and how much to increase size.