I would be nice for customers if there was a leading foundry like TSMC. But TSMC moved ahead based on skill and execution, So you cannot mandate a competitor. Everyone is free to choose Intel (no one chose them) or Samsung or UMC or GF. TSMC is a much better company. Just like Nvidia is a much better computer company.
Intel is fully enabled to be a competitor as is Samsung. UMC and GF could use some help to pay for leading nodes but they probably will not execute much better.... plus the equipment ecosystem likes one leader.
If a company is just outperforming everyone, they are not going to have competition.
I have said for awhile there is no such thing as a "NOT market leader" market.
Yes companies like to have a second source, but the second source is generally the cheaper option that might not be quite as performant. In this case the second source is competing on price while the primary source is competing on performance and customers throw the second source a bone once in awhile to maintain price competition in the market. To some extent this is what Samsung has been doing historically, but the performance gap got too large.
Intel cannot be a second source if they are more expensive than TSMC. They either need to beat TSMC on performance, or provide acceptable performance at a better price. They cannot win by simply being "NOT TSMC". Nobody will pay Intel more money for less performance on the virtue of being NOT TSMC.