Sorry to hear that. My mother has arthritis and struggles to open jars. I bought her a simple device that works a treat. https://www.ikea.com/gb/en/images/products/uppfylld-jar-opener-off-white-bright-orange__1124811_pe875267_s5.jpg?f=l

Lever-up the edge with a regular tin opener. This breaks the seal, allows air in (reduces the pressure difference) and...makes the lid easier to open by hand.

Hardly, unless you're aware of limitations the project scientists aren't. You can see the current challenges (not akin to your analogy), listed on the initiative's site though, while challenging, are deemed to be, "based on technology either already available or likely to be attainable in the near future under reasonable assumptions."

"No ‘dealbreakers’ have been identified by the team of expert scientists and engineers leading the program."

https://breakthroughinitiatives.org/challenges/3

The biggest barrier is funding. The project has outlined the design and made recommendtions on the materials improvements required; such improvements would be inevitable with appropriate funding. However, the project wasn't funded to build and launch; it was only funded to answer a question posed by the billionaire who paid for it, that question essentially being: is it possible to reach our nearest neighbouring star system in my lifetime? The answer to that question was answered and promoted by the likes of Avi Loeb and Stephen Hawking: with adequate funding, yes.

Video of Hawking stating we can reach Alpha Centauri in a generation:

https://youtu.be/c02tYKUGUNM

Project Breakthrough Starshot estimates a 20-30 year timeline for reaching Alpha Centauri. There are some material science challenges to overcome but the biggest barrier is funding. https://astronomy.com/magazine/news/2021/06/breakthrough-starshot-a-voyage-to-the-stars-within-our-lifetimes